[chore]: Bump github.com/miekg/dns from 1.1.55 to 1.1.56 (#2204)

Co-authored-by: dependabot[bot] <49699333+dependabot[bot]@users.noreply.github.com>

go.mod

@@ -35,7 +35,7 @@ require (
 	github.com/jackc/pgconn v1.14.1
 	github.com/jackc/pgx/v5 v5.4.3
 	github.com/microcosm-cc/bluemonday v1.0.25
-	github.com/miekg/dns v1.1.55
+	github.com/miekg/dns v1.1.56
 	github.com/minio/minio-go/v7 v7.0.63
 	github.com/mitchellh/mapstructure v1.5.0
 	github.com/oklog/ulid v1.3.1
@@ -164,9 +164,9 @@ require (
 	go.opentelemetry.io/otel/metric v1.17.0 // indirect
 	go.opentelemetry.io/proto/otlp v1.0.0 // indirect
 	golang.org/x/arch v0.3.0 // indirect
-	golang.org/x/mod v0.10.0 // indirect
+	golang.org/x/mod v0.12.0 // indirect
 	golang.org/x/sys v0.12.0 // indirect
-	golang.org/x/tools v0.6.0 // indirect
+	golang.org/x/tools v0.13.0 // indirect
 	google.golang.org/appengine v1.6.7 // indirect
 	google.golang.org/genproto/googleapis/api v0.0.0-20230530153820-e85fd2cbaebc // indirect
 	google.golang.org/genproto/googleapis/rpc v0.0.0-20230530153820-e85fd2cbaebc // indirect

go.sum

@@ -431,8 +431,8 @@ github.com/mattn/go-isatty v0.0.19/go.mod h1:W+V8PltTTMOvKvAeJH7IuucS94S2C6jfK/D
 github.com/mattn/go-sqlite3 v2.0.3+incompatible h1:gXHsfypPkaMZrKbD5209QV9jbUTJKjyR5WD3HYQSd+U=
 github.com/microcosm-cc/bluemonday v1.0.25 h1:4NEwSfiJ+Wva0VxN5B8OwMicaJvD8r9tlJWm9rtloEg=
 github.com/microcosm-cc/bluemonday v1.0.25/go.mod h1:ZIOjCQp1OrzBBPIJmfX4qDYFuhU02nx4bn030ixfHLE=
-github.com/miekg/dns v1.1.55 h1:GoQ4hpsj0nFLYe+bWiCToyrBEJXkQfOOIvFGFy0lEgo=
+github.com/miekg/dns v1.1.56 h1:5imZaSeoRNvpM9SzWNhEcP9QliKiz20/dA2QabIGVnE=
-github.com/miekg/dns v1.1.55/go.mod h1:uInx36IzPl7FYnDcMeVWxj9byh7DutNykX4G9Sj60FY=
+github.com/miekg/dns v1.1.56/go.mod h1:cRm6Oo2C8TY9ZS/TqsSrseAcncm74lfK5G+ikN2SWWY=
 github.com/minio/md5-simd v1.1.2 h1:Gdi1DZK69+ZVMoNHRXJyNcxrMA4dSxoYHZSQbirFg34=
 github.com/minio/md5-simd v1.1.2/go.mod h1:MzdKDxYpY2BT9XQFocsiZf/NKVtR7nkE4RoEpN+20RM=
 github.com/minio/minio-go/v7 v7.0.63 h1:GbZ2oCvaUdgT5640WJOpyDhhDxvknAJU2/T3yurwcbQ=
@@ -714,8 +714,8 @@ golang.org/x/mod v0.4.0/go.mod h1:s0Qsj1ACt9ePp/hMypM3fl4fZqREWJwdYDEqhRiZZUA=
 golang.org/x/mod v0.4.1/go.mod h1:s0Qsj1ACt9ePp/hMypM3fl4fZqREWJwdYDEqhRiZZUA=
 golang.org/x/mod v0.6.0-dev.0.20220419223038-86c51ed26bb4/go.mod h1:jJ57K6gSWd91VN4djpZkiMVwK6gcyfeH4XE8wZrZaV4=
 golang.org/x/mod v0.8.0/go.mod h1:iBbtSCu2XBx23ZKBPSOrRkjjQPZFPuis4dIYUhu/chs=
-golang.org/x/mod v0.10.0 h1:lFO9qtOdlre5W1jxS3r/4szv2/6iXxScdzjoBMXNhYk=
+golang.org/x/mod v0.12.0 h1:rmsUpXtvNzj340zd98LZ4KntptpfRHwpFOHG188oHXc=
-golang.org/x/mod v0.10.0/go.mod h1:iBbtSCu2XBx23ZKBPSOrRkjjQPZFPuis4dIYUhu/chs=
+golang.org/x/mod v0.12.0/go.mod h1:iBbtSCu2XBx23ZKBPSOrRkjjQPZFPuis4dIYUhu/chs=
 golang.org/x/net v0.0.0-20180724234803-3673e40ba225/go.mod h1:mL1N/T3taQHkDXs73rZJwtUhF3w3ftmwwsq0BUmARs4=
 golang.org/x/net v0.0.0-20180826012351-8a410e7b638d/go.mod h1:mL1N/T3taQHkDXs73rZJwtUhF3w3ftmwwsq0BUmARs4=
 golang.org/x/net v0.0.0-20180906233101-161cd47e91fd/go.mod h1:mL1N/T3taQHkDXs73rZJwtUhF3w3ftmwwsq0BUmARs4=
@@ -779,8 +779,8 @@ golang.org/x/sync v0.0.0-20200625203802-6e8e738ad208/go.mod h1:RxMgew5VJxzue5/jJ
 golang.org/x/sync v0.0.0-20201020160332-67f06af15bc9/go.mod h1:RxMgew5VJxzue5/jJTE5uejpjVlOe/izrB70Jof72aM=
 golang.org/x/sync v0.0.0-20201207232520-09787c993a3a/go.mod h1:RxMgew5VJxzue5/jJTE5uejpjVlOe/izrB70Jof72aM=
 golang.org/x/sync v0.0.0-20220722155255-886fb9371eb4/go.mod h1:RxMgew5VJxzue5/jJTE5uejpjVlOe/izrB70Jof72aM=
-golang.org/x/sync v0.1.0 h1:wsuoTGHzEhffawBOhz5CYhcrV4IdKZbEyZjBMuTp12o=
 golang.org/x/sync v0.1.0/go.mod h1:RxMgew5VJxzue5/jJTE5uejpjVlOe/izrB70Jof72aM=
+golang.org/x/sync v0.3.0 h1:ftCYgMx6zT/asHUrPw8BLLscYtGznsLAnjq5RH9P66E=
 golang.org/x/sys v0.0.0-20180830151530-49385e6e1522/go.mod h1:STP8DvDyc/dI5b8T5hshtkjS+E42TnysNCUPdjciGhY=
 golang.org/x/sys v0.0.0-20180905080454-ebe1bf3edb33/go.mod h1:STP8DvDyc/dI5b8T5hshtkjS+E42TnysNCUPdjciGhY=
 golang.org/x/sys v0.0.0-20180909124046-d0be0721c37e/go.mod h1:STP8DvDyc/dI5b8T5hshtkjS+E42TnysNCUPdjciGhY=
@@ -910,8 +910,9 @@ golang.org/x/tools v0.0.0-20210105154028-b0ab187a4818/go.mod h1:emZCQorbCU4vsT4f
 golang.org/x/tools v0.0.0-20210108195828-e2f9c7f1fc8e/go.mod h1:emZCQorbCU4vsT4fOWvOPXz4eW1wZW4PmDk9uLelYpA=
 golang.org/x/tools v0.1.0/go.mod h1:xkSsbof2nBLbhDlRMhhhyNLN/zl3eTqcnHD5viDpcZ0=
 golang.org/x/tools v0.1.12/go.mod h1:hNGJHUnrk76NpqgfD5Aqm5Crs+Hm0VOH/i9J2+nxYbc=
-golang.org/x/tools v0.6.0 h1:BOw41kyTf3PuCW1pVQf8+Cyg8pMlkYB1oo9iJ6D/lKM=
 golang.org/x/tools v0.6.0/go.mod h1:Xwgl3UAJ/d3gWutnCtw505GrjyAbvKui8lOU390QaIU=
+golang.org/x/tools v0.13.0 h1:Iey4qkscZuv0VvIt8E0neZjtPVQFSc870HQ448QgEmQ=
+golang.org/x/tools v0.13.0/go.mod h1:HvlwmtVNQAhOuCjW7xxvovg8wbNq7LwfXh/k7wXUl58=
 golang.org/x/xerrors v0.0.0-20190410155217-1f06c39b4373/go.mod h1:I/5z698sn9Ka8TeJc9MKroUUfqBBauWjQqLJ2OPfmY0=
 golang.org/x/xerrors v0.0.0-20190513163551-3ee3066db522/go.mod h1:I/5z698sn9Ka8TeJc9MKroUUfqBBauWjQqLJ2OPfmY0=
 golang.org/x/xerrors v0.0.0-20190717185122-a985d3407aa7/go.mod h1:I/5z698sn9Ka8TeJc9MKroUUfqBBauWjQqLJ2OPfmY0=

vendor/github.com/miekg/dns/README.md

@@ -81,6 +81,7 @@ A not-so-up-to-date-list-that-may-be-actually-current:
 * https://addr.tools/
 * https://dnscheck.tools/
 * https://github.com/egbakou/domainverifier
+* https://github.com/semihalev/sdns
 
 
 Send pull request if you want to be listed here.

vendor/github.com/miekg/dns/defaults.go

@@ -5,6 +5,7 @@ import (
 	"net"
 	"strconv"
 	"strings"
+	"unicode"
 )
 
 const hexDigit = "0123456789abcdef"
@@ -330,8 +331,18 @@ func Fqdn(s string) string {
 
 // CanonicalName returns the domain name in canonical form. A name in canonical
 // form is lowercase and fully qualified. See Section 6.2 in RFC 4034.
+// According to the RFC all uppercase US-ASCII letters in the owner name of the
+// RR areeplaced by the corresponding lowercase US-ASCII letters.
 func CanonicalName(s string) string {
-	return strings.ToLower(Fqdn(s))
+	var result strings.Builder
+	for _, ch := range s {
+		if unicode.IsUpper(ch) && (ch >= 0x00 && ch <= 0x7F) {
+			result.WriteRune(unicode.ToLower(ch))
+		} else {
+			result.WriteRune(ch)
+		}
+	}
+	return Fqdn(result.String())
 }
 
 // Copied from the official Go code.

vendor/github.com/miekg/dns/msg.go

@@ -896,23 +896,38 @@ func (dns *Msg) String() string {
 		return "<nil> MsgHdr"
 	}
 	s := dns.MsgHdr.String() + " "
-	s += "QUERY: " + strconv.Itoa(len(dns.Question)) + ", "
+	if dns.MsgHdr.Opcode == OpcodeUpdate {
-	s += "ANSWER: " + strconv.Itoa(len(dns.Answer)) + ", "
+		s += "ZONE: " + strconv.Itoa(len(dns.Question)) + ", "
-	s += "AUTHORITY: " + strconv.Itoa(len(dns.Ns)) + ", "
+		s += "PREREQ: " + strconv.Itoa(len(dns.Answer)) + ", "
-	s += "ADDITIONAL: " + strconv.Itoa(len(dns.Extra)) + "\n"
+		s += "UPDATE: " + strconv.Itoa(len(dns.Ns)) + ", "
+		s += "ADDITIONAL: " + strconv.Itoa(len(dns.Extra)) + "\n"
+	} else {
+		s += "QUERY: " + strconv.Itoa(len(dns.Question)) + ", "
+		s += "ANSWER: " + strconv.Itoa(len(dns.Answer)) + ", "
+		s += "AUTHORITY: " + strconv.Itoa(len(dns.Ns)) + ", "
+		s += "ADDITIONAL: " + strconv.Itoa(len(dns.Extra)) + "\n"
+	}
 	opt := dns.IsEdns0()
 	if opt != nil {
 		// OPT PSEUDOSECTION
 		s += opt.String() + "\n"
 	}
 	if len(dns.Question) > 0 {
-		s += "\n;; QUESTION SECTION:\n"
+		if dns.MsgHdr.Opcode == OpcodeUpdate {
+			s += "\n;; ZONE SECTION:\n"
+		} else {
+			s += "\n;; QUESTION SECTION:\n"
+		}
 		for _, r := range dns.Question {
 			s += r.String() + "\n"
 		}
 	}
 	if len(dns.Answer) > 0 {
-		s += "\n;; ANSWER SECTION:\n"
+		if dns.MsgHdr.Opcode == OpcodeUpdate {
+			s += "\n;; PREREQUISITE SECTION:\n"
+		} else {
+			s += "\n;; ANSWER SECTION:\n"
+		}
 		for _, r := range dns.Answer {
 			if r != nil {
 				s += r.String() + "\n"
@@ -920,7 +935,11 @@ func (dns *Msg) String() string {
 		}
 	}
 	if len(dns.Ns) > 0 {
-		s += "\n;; AUTHORITY SECTION:\n"
+		if dns.MsgHdr.Opcode == OpcodeUpdate {
+			s += "\n;; UPDATE SECTION:\n"
+		} else {
+			s += "\n;; AUTHORITY SECTION:\n"
+		}
 		for _, r := range dns.Ns {
 			if r != nil {
 				s += r.String() + "\n"

vendor/github.com/miekg/dns/types.go

@@ -236,6 +236,9 @@ var CertTypeToString = map[uint16]string{
 	CertOID:     "OID",
 }
 
+// Prefix for IPv4 encoded as IPv6 address
+const ipv4InIPv6Prefix = "::ffff:"
+
 //go:generate go run types_generate.go
 
 // Question holds a DNS question. Usually there is just one. While the
@@ -751,6 +754,11 @@ func (rr *AAAA) String() string {
 	if rr.AAAA == nil {
 		return rr.Hdr.String()
 	}
+
+	if rr.AAAA.To4() != nil {
+		return rr.Hdr.String() + ipv4InIPv6Prefix + rr.AAAA.String()
+	}
+
 	return rr.Hdr.String() + rr.AAAA.String()
 }
 
@@ -1517,7 +1525,7 @@ func (a *APLPrefix) str() string {
 	case net.IPv6len:
 		// add prefix for IPv4-mapped IPv6
 		if v4 := a.Network.IP.To4(); v4 != nil {
-			sb.WriteString("::ffff:")
+			sb.WriteString(ipv4InIPv6Prefix)
 		}
 		sb.WriteString(a.Network.IP.String())
 	}

vendor/github.com/miekg/dns/version.go

@@ -3,7 +3,7 @@ package dns
 import "fmt"
 
 // Version is current version of this library.
-var Version = v{1, 1, 55}
+var Version = v{1, 1, 56}
 
 // v holds the version of this library.
 type v struct {

vendor/golang.org/x/mod/semver/semver.go

@@ -140,7 +140,7 @@ func Compare(v, w string) int {
 // Max canonicalizes its arguments and then returns the version string
 // that compares greater.
 //
-// Deprecated: use Compare instead. In most cases, returning a canonicalized
+// Deprecated: use [Compare] instead. In most cases, returning a canonicalized
 // version is not expected or desired.
 func Max(v, w string) string {
 	v = Canonical(v)
@@ -151,7 +151,7 @@ func Max(v, w string) string {
 	return w
 }
 
-// ByVersion implements sort.Interface for sorting semantic version strings.
+// ByVersion implements [sort.Interface] for sorting semantic version strings.
 type ByVersion []string
 
 func (vs ByVersion) Len() int      { return len(vs) }
@@ -164,7 +164,7 @@ func (vs ByVersion) Less(i, j int) bool {
 	return vs[i] < vs[j]
 }
 
-// Sort sorts a list of semantic version strings using ByVersion.
+// Sort sorts a list of semantic version strings using [ByVersion].
 func Sort(list []string) {
 	sort.Sort(ByVersion(list))
 }

vendor/golang.org/x/tools/go/gcexportdata/gcexportdata.go

@@ -128,15 +128,14 @@ func Read(in io.Reader, fset *token.FileSet, imports map[string]*types.Package,
 	// (from "version"). Select appropriate importer.
 	if len(data) > 0 {
 		switch data[0] {
-		case 'i':
+		case 'v', 'c', 'd': // binary, till go1.10
+			return nil, fmt.Errorf("binary (%c) import format is no longer supported", data[0])
+
+		case 'i': // indexed, till go1.19
 			_, pkg, err := gcimporter.IImportData(fset, imports, data[1:], path)
 			return pkg, err
 
-		case 'v', 'c', 'd':
+		case 'u': // unified, from go1.20
-			_, pkg, err := gcimporter.BImportData(fset, imports, data, path)
-			return pkg, err
-
-		case 'u':
 			_, pkg, err := gcimporter.UImportData(fset, imports, data[1:], path)
 			return pkg, err
 

vendor/golang.org/x/tools/go/internal/packagesdriver/sizes.go

@@ -8,7 +8,6 @@ package packagesdriver
 import (
 	"context"
 	"fmt"
-	"go/types"
 	"strings"
 
 	"golang.org/x/tools/internal/gocommand"
@@ -16,7 +15,7 @@ import (
 
 var debug = false
 
-func GetSizesGolist(ctx context.Context, inv gocommand.Invocation, gocmdRunner *gocommand.Runner) (types.Sizes, error) {
+func GetSizesForArgsGolist(ctx context.Context, inv gocommand.Invocation, gocmdRunner *gocommand.Runner) (string, string, error) {
 	inv.Verb = "list"
 	inv.Args = []string{"-f", "{{context.GOARCH}} {{context.Compiler}}", "--", "unsafe"}
 	stdout, stderr, friendlyErr, rawErr := gocmdRunner.RunRaw(ctx, inv)
@@ -29,21 +28,21 @@ func GetSizesGolist(ctx context.Context, inv gocommand.Invocation, gocmdRunner *
 			inv.Args = []string{"GOARCH"}
 			envout, enverr := gocmdRunner.Run(ctx, inv)
 			if enverr != nil {
-				return nil, enverr
+				return "", "", enverr
 			}
 			goarch = strings.TrimSpace(envout.String())
 			compiler = "gc"
 		} else {
-			return nil, friendlyErr
+			return "", "", friendlyErr
 		}
 	} else {
 		fields := strings.Fields(stdout.String())
 		if len(fields) < 2 {
-			return nil, fmt.Errorf("could not parse GOARCH and Go compiler in format \"<GOARCH> <compiler>\":\nstdout: <<%s>>\nstderr: <<%s>>",
+			return "", "", fmt.Errorf("could not parse GOARCH and Go compiler in format \"<GOARCH> <compiler>\":\nstdout: <<%s>>\nstderr: <<%s>>",
 				stdout.String(), stderr.String())
 		}
 		goarch = fields[0]
 		compiler = fields[1]
 	}
-	return types.SizesFor(compiler, goarch), nil
+	return compiler, goarch, nil
 }

vendor/golang.org/x/tools/go/packages/golist.go

@@ -9,7 +9,6 @@ import (
 	"context"
 	"encoding/json"
 	"fmt"
-	"go/types"
 	"io/ioutil"
 	"log"
 	"os"
@@ -153,10 +152,10 @@ func goListDriver(cfg *Config, patterns ...string) (*driverResponse, error) {
 	if cfg.Mode&NeedTypesSizes != 0 || cfg.Mode&NeedTypes != 0 {
 		sizeswg.Add(1)
 		go func() {
-			var sizes types.Sizes
+			compiler, arch, err := packagesdriver.GetSizesForArgsGolist(ctx, state.cfgInvocation(), cfg.gocmdRunner)
-			sizes, sizeserr = packagesdriver.GetSizesGolist(ctx, state.cfgInvocation(), cfg.gocmdRunner)
+			sizeserr = err
-			// types.SizesFor always returns nil or a *types.StdSizes.
+			response.dr.Compiler = compiler
-			response.dr.Sizes, _ = sizes.(*types.StdSizes)
+			response.dr.Arch = arch
 			sizeswg.Done()
 		}()
 	}
@@ -625,7 +624,12 @@ func (state *golistState) createDriverResponse(words ...string) (*driverResponse
 		}
 
 		if pkg.PkgPath == "unsafe" {
-			pkg.GoFiles = nil // ignore fake unsafe.go file
+			pkg.CompiledGoFiles = nil // ignore fake unsafe.go file (#59929)
+		} else if len(pkg.CompiledGoFiles) == 0 {
+			// Work around for pre-go.1.11 versions of go list.
+			// TODO(matloob): they should be handled by the fallback.
+			// Can we delete this?
+			pkg.CompiledGoFiles = pkg.GoFiles
 		}
 
 		// Assume go list emits only absolute paths for Dir.
@@ -663,16 +667,12 @@ func (state *golistState) createDriverResponse(words ...string) (*driverResponse
 			response.Roots = append(response.Roots, pkg.ID)
 		}
 
-		// Work around for pre-go.1.11 versions of go list.
-		// TODO(matloob): they should be handled by the fallback.
-		// Can we delete this?
-		if len(pkg.CompiledGoFiles) == 0 {
-			pkg.CompiledGoFiles = pkg.GoFiles
-		}
-
 		// Temporary work-around for golang/go#39986. Parse filenames out of
 		// error messages. This happens if there are unrecoverable syntax
 		// errors in the source, so we can't match on a specific error message.
+		//
+		// TODO(rfindley): remove this heuristic, in favor of considering
+		// InvalidGoFiles from the list driver.
 		if err := p.Error; err != nil && state.shouldAddFilenameFromError(p) {
 			addFilenameFromPos := func(pos string) bool {
 				split := strings.Split(pos, ":")
@@ -891,6 +891,15 @@ func golistargs(cfg *Config, words []string, goVersion int) []string {
 		// probably because you'd just get the TestMain.
 		fmt.Sprintf("-find=%t", !cfg.Tests && cfg.Mode&findFlags == 0 && !usesExportData(cfg)),
 	}
+
+	// golang/go#60456: with go1.21 and later, go list serves pgo variants, which
+	// can be costly to compute and may result in redundant processing for the
+	// caller. Disable these variants. If someone wants to add e.g. a NeedPGO
+	// mode flag, that should be a separate proposal.
+	if goVersion >= 21 {
+		fullargs = append(fullargs, "-pgo=off")
+	}
+
 	fullargs = append(fullargs, cfg.BuildFlags...)
 	fullargs = append(fullargs, "--")
 	fullargs = append(fullargs, words...)

vendor/golang.org/x/tools/go/packages/packages.go

@@ -220,8 +220,10 @@ type driverResponse struct {
 	// lists of multiple drivers, go/packages will fall back to the next driver.
 	NotHandled bool
 
-	// Sizes, if not nil, is the types.Sizes to use when type checking.
+	// Compiler and Arch are the arguments pass of types.SizesFor
-	Sizes *types.StdSizes
+	// to get a types.Sizes to use when type checking.
+	Compiler string
+	Arch     string
 
 	// Roots is the set of package IDs that make up the root packages.
 	// We have to encode this separately because when we encode a single package
@@ -262,7 +264,7 @@ func Load(cfg *Config, patterns ...string) ([]*Package, error) {
 	if err != nil {
 		return nil, err
 	}
-	l.sizes = response.Sizes
+	l.sizes = types.SizesFor(response.Compiler, response.Arch)
 	return l.refine(response)
 }
 
@@ -308,6 +310,9 @@ type Package struct {
 	TypeErrors []types.Error
 
 	// GoFiles lists the absolute file paths of the package's Go source files.
+	// It may include files that should not be compiled, for example because
+	// they contain non-matching build tags, are documentary pseudo-files such as
+	// unsafe/unsafe.go or builtin/builtin.go, or are subject to cgo preprocessing.
 	GoFiles []string
 
 	// CompiledGoFiles lists the absolute file paths of the package's source
@@ -627,7 +632,7 @@ func newLoader(cfg *Config) *loader {
 	return ld
 }
 
-// refine connects the supplied packages into a graph and then adds type and
+// refine connects the supplied packages into a graph and then adds type
 // and syntax information as requested by the LoadMode.
 func (ld *loader) refine(response *driverResponse) ([]*Package, error) {
 	roots := response.Roots
@@ -1040,6 +1045,9 @@ func (ld *loader) loadPackage(lpkg *loaderPackage) {
 		Error: appendError,
 		Sizes: ld.sizes,
 	}
+	if lpkg.Module != nil && lpkg.Module.GoVersion != "" {
+		typesinternal.SetGoVersion(tc, "go"+lpkg.Module.GoVersion)
+	}
 	if (ld.Mode & typecheckCgo) != 0 {
 		if !typesinternal.SetUsesCgo(tc) {
 			appendError(Error{

vendor/golang.org/x/tools/go/types/objectpath/objectpath.go

@@ -0,0 +1,827 @@
+// Copyright 2018 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+// Package objectpath defines a naming scheme for types.Objects
+// (that is, named entities in Go programs) relative to their enclosing
+// package.
+//
+// Type-checker objects are canonical, so they are usually identified by
+// their address in memory (a pointer), but a pointer has meaning only
+// within one address space. By contrast, objectpath names allow the
+// identity of an object to be sent from one program to another,
+// establishing a correspondence between types.Object variables that are
+// distinct but logically equivalent.
+//
+// A single object may have multiple paths. In this example,
+//
+//	type A struct{ X int }
+//	type B A
+//
+// the field X has two paths due to its membership of both A and B.
+// The For(obj) function always returns one of these paths, arbitrarily
+// but consistently.
+package objectpath
+
+import (
+	"fmt"
+	"go/types"
+	"sort"
+	"strconv"
+	"strings"
+	_ "unsafe"
+
+	"golang.org/x/tools/internal/typeparams"
+	"golang.org/x/tools/internal/typesinternal"
+)
+
+// A Path is an opaque name that identifies a types.Object
+// relative to its package. Conceptually, the name consists of a
+// sequence of destructuring operations applied to the package scope
+// to obtain the original object.
+// The name does not include the package itself.
+type Path string
+
+// Encoding
+//
+// An object path is a textual and (with training) human-readable encoding
+// of a sequence of destructuring operators, starting from a types.Package.
+// The sequences represent a path through the package/object/type graph.
+// We classify these operators by their type:
+//
+//	PO package->object	Package.Scope.Lookup
+//	OT  object->type 	Object.Type
+//	TT    type->type 	Type.{Elem,Key,Params,Results,Underlying} [EKPRU]
+//	TO   type->object	Type.{At,Field,Method,Obj} [AFMO]
+//
+// All valid paths start with a package and end at an object
+// and thus may be defined by the regular language:
+//
+//	objectpath = PO (OT TT* TO)*
+//
+// The concrete encoding follows directly:
+//   - The only PO operator is Package.Scope.Lookup, which requires an identifier.
+//   - The only OT operator is Object.Type,
+//     which we encode as '.' because dot cannot appear in an identifier.
+//   - The TT operators are encoded as [EKPRUTC];
+//     one of these (TypeParam) requires an integer operand,
+//     which is encoded as a string of decimal digits.
+//   - The TO operators are encoded as [AFMO];
+//     three of these (At,Field,Method) require an integer operand,
+//     which is encoded as a string of decimal digits.
+//     These indices are stable across different representations
+//     of the same package, even source and export data.
+//     The indices used are implementation specific and may not correspond to
+//     the argument to the go/types function.
+//
+// In the example below,
+//
+//	package p
+//
+//	type T interface {
+//		f() (a string, b struct{ X int })
+//	}
+//
+// field X has the path "T.UM0.RA1.F0",
+// representing the following sequence of operations:
+//
+//	p.Lookup("T")					T
+//	.Type().Underlying().Method(0).			f
+//	.Type().Results().At(1)				b
+//	.Type().Field(0)					X
+//
+// The encoding is not maximally compact---every R or P is
+// followed by an A, for example---but this simplifies the
+// encoder and decoder.
+const (
+	// object->type operators
+	opType = '.' // .Type()		  (Object)
+
+	// type->type operators
+	opElem       = 'E' // .Elem()		        (Pointer, Slice, Array, Chan, Map)
+	opKey        = 'K' // .Key()		        (Map)
+	opParams     = 'P' // .Params()		      (Signature)
+	opResults    = 'R' // .Results()	      (Signature)
+	opUnderlying = 'U' // .Underlying()	    (Named)
+	opTypeParam  = 'T' // .TypeParams.At(i) (Named, Signature)
+	opConstraint = 'C' // .Constraint()     (TypeParam)
+
+	// type->object operators
+	opAt     = 'A' // .At(i)		 (Tuple)
+	opField  = 'F' // .Field(i)	 (Struct)
+	opMethod = 'M' // .Method(i) (Named or Interface; not Struct: "promoted" names are ignored)
+	opObj    = 'O' // .Obj()		 (Named, TypeParam)
+)
+
+// For is equivalent to new(Encoder).For(obj).
+//
+// It may be more efficient to reuse a single Encoder across several calls.
+func For(obj types.Object) (Path, error) {
+	return new(Encoder).For(obj)
+}
+
+// An Encoder amortizes the cost of encoding the paths of multiple objects.
+// The zero value of an Encoder is ready to use.
+type Encoder struct {
+	scopeMemo         map[*types.Scope][]types.Object // memoization of scopeObjects
+	namedMethodsMemo  map[*types.Named][]*types.Func  // memoization of namedMethods()
+	skipMethodSorting bool
+}
+
+// Expose back doors so that gopls can avoid method sorting, which can dominate
+// analysis on certain repositories.
+//
+// TODO(golang/go#61443): remove this.
+func init() {
+	typesinternal.SkipEncoderMethodSorting = func(enc interface{}) {
+		enc.(*Encoder).skipMethodSorting = true
+	}
+	typesinternal.ObjectpathObject = object
+}
+
+// For returns the path to an object relative to its package,
+// or an error if the object is not accessible from the package's Scope.
+//
+// The For function guarantees to return a path only for the following objects:
+// - package-level types
+// - exported package-level non-types
+// - methods
+// - parameter and result variables
+// - struct fields
+// These objects are sufficient to define the API of their package.
+// The objects described by a package's export data are drawn from this set.
+//
+// The set of objects accessible from a package's Scope depends on
+// whether the package was produced by type-checking syntax, or
+// reading export data; the latter may have a smaller Scope since
+// export data trims objects that are not reachable from an exported
+// declaration. For example, the For function will return a path for
+// an exported method of an unexported type that is not reachable
+// from any public declaration; this path will cause the Object
+// function to fail if called on a package loaded from export data.
+// TODO(adonovan): is this a bug or feature? Should this package
+// compute accessibility in the same way?
+//
+// For does not return a path for predeclared names, imported package
+// names, local names, and unexported package-level names (except
+// types).
+//
+// Example: given this definition,
+//
+//	package p
+//
+//	type T interface {
+//		f() (a string, b struct{ X int })
+//	}
+//
+// For(X) would return a path that denotes the following sequence of operations:
+//
+//	p.Scope().Lookup("T")				(TypeName T)
+//	.Type().Underlying().Method(0).			(method Func f)
+//	.Type().Results().At(1)				(field Var b)
+//	.Type().Field(0)					(field Var X)
+//
+// where p is the package (*types.Package) to which X belongs.
+func (enc *Encoder) For(obj types.Object) (Path, error) {
+	pkg := obj.Pkg()
+
+	// This table lists the cases of interest.
+	//
+	// Object				Action
+	// ------                               ------
+	// nil					reject
+	// builtin				reject
+	// pkgname				reject
+	// label				reject
+	// var
+	//    package-level			accept
+	//    func param/result			accept
+	//    local				reject
+	//    struct field			accept
+	// const
+	//    package-level			accept
+	//    local				reject
+	// func
+	//    package-level			accept
+	//    init functions			reject
+	//    concrete method			accept
+	//    interface method			accept
+	// type
+	//    package-level			accept
+	//    local				reject
+	//
+	// The only accessible package-level objects are members of pkg itself.
+	//
+	// The cases are handled in four steps:
+	//
+	// 1. reject nil and builtin
+	// 2. accept package-level objects
+	// 3. reject obviously invalid objects
+	// 4. search the API for the path to the param/result/field/method.
+
+	// 1. reference to nil or builtin?
+	if pkg == nil {
+		return "", fmt.Errorf("predeclared %s has no path", obj)
+	}
+	scope := pkg.Scope()
+
+	// 2. package-level object?
+	if scope.Lookup(obj.Name()) == obj {
+		// Only exported objects (and non-exported types) have a path.
+		// Non-exported types may be referenced by other objects.
+		if _, ok := obj.(*types.TypeName); !ok && !obj.Exported() {
+			return "", fmt.Errorf("no path for non-exported %v", obj)
+		}
+		return Path(obj.Name()), nil
+	}
+
+	// 3. Not a package-level object.
+	//    Reject obviously non-viable cases.
+	switch obj := obj.(type) {
+	case *types.TypeName:
+		if _, ok := obj.Type().(*typeparams.TypeParam); !ok {
+			// With the exception of type parameters, only package-level type names
+			// have a path.
+			return "", fmt.Errorf("no path for %v", obj)
+		}
+	case *types.Const, // Only package-level constants have a path.
+		*types.Label,   // Labels are function-local.
+		*types.PkgName: // PkgNames are file-local.
+		return "", fmt.Errorf("no path for %v", obj)
+
+	case *types.Var:
+		// Could be:
+		// - a field (obj.IsField())
+		// - a func parameter or result
+		// - a local var.
+		// Sadly there is no way to distinguish
+		// a param/result from a local
+		// so we must proceed to the find.
+
+	case *types.Func:
+		// A func, if not package-level, must be a method.
+		if recv := obj.Type().(*types.Signature).Recv(); recv == nil {
+			return "", fmt.Errorf("func is not a method: %v", obj)
+		}
+
+		if path, ok := enc.concreteMethod(obj); ok {
+			// Fast path for concrete methods that avoids looping over scope.
+			return path, nil
+		}
+
+	default:
+		panic(obj)
+	}
+
+	// 4. Search the API for the path to the var (field/param/result) or method.
+
+	// First inspect package-level named types.
+	// In the presence of path aliases, these give
+	// the best paths because non-types may
+	// refer to types, but not the reverse.
+	empty := make([]byte, 0, 48) // initial space
+	objs := enc.scopeObjects(scope)
+	for _, o := range objs {
+		tname, ok := o.(*types.TypeName)
+		if !ok {
+			continue // handle non-types in second pass
+		}
+
+		path := append(empty, o.Name()...)
+		path = append(path, opType)
+
+		T := o.Type()
+
+		if tname.IsAlias() {
+			// type alias
+			if r := find(obj, T, path, nil); r != nil {
+				return Path(r), nil
+			}
+		} else {
+			if named, _ := T.(*types.Named); named != nil {
+				if r := findTypeParam(obj, typeparams.ForNamed(named), path, nil); r != nil {
+					// generic named type
+					return Path(r), nil
+				}
+			}
+			// defined (named) type
+			if r := find(obj, T.Underlying(), append(path, opUnderlying), nil); r != nil {
+				return Path(r), nil
+			}
+		}
+	}
+
+	// Then inspect everything else:
+	// non-types, and declared methods of defined types.
+	for _, o := range objs {
+		path := append(empty, o.Name()...)
+		if _, ok := o.(*types.TypeName); !ok {
+			if o.Exported() {
+				// exported non-type (const, var, func)
+				if r := find(obj, o.Type(), append(path, opType), nil); r != nil {
+					return Path(r), nil
+				}
+			}
+			continue
+		}
+
+		// Inspect declared methods of defined types.
+		if T, ok := o.Type().(*types.Named); ok {
+			path = append(path, opType)
+			if !enc.skipMethodSorting {
+				// Note that method index here is always with respect
+				// to canonical ordering of methods, regardless of how
+				// they appear in the underlying type.
+				for i, m := range enc.namedMethods(T) {
+					path2 := appendOpArg(path, opMethod, i)
+					if m == obj {
+						return Path(path2), nil // found declared method
+					}
+					if r := find(obj, m.Type(), append(path2, opType), nil); r != nil {
+						return Path(r), nil
+					}
+				}
+			} else {
+				// This branch must match the logic in the branch above, using go/types
+				// APIs without sorting.
+				for i := 0; i < T.NumMethods(); i++ {
+					m := T.Method(i)
+					path2 := appendOpArg(path, opMethod, i)
+					if m == obj {
+						return Path(path2), nil // found declared method
+					}
+					if r := find(obj, m.Type(), append(path2, opType), nil); r != nil {
+						return Path(r), nil
+					}
+				}
+			}
+		}
+	}
+
+	return "", fmt.Errorf("can't find path for %v in %s", obj, pkg.Path())
+}
+
+func appendOpArg(path []byte, op byte, arg int) []byte {
+	path = append(path, op)
+	path = strconv.AppendInt(path, int64(arg), 10)
+	return path
+}
+
+// concreteMethod returns the path for meth, which must have a non-nil receiver.
+// The second return value indicates success and may be false if the method is
+// an interface method or if it is an instantiated method.
+//
+// This function is just an optimization that avoids the general scope walking
+// approach. You are expected to fall back to the general approach if this
+// function fails.
+func (enc *Encoder) concreteMethod(meth *types.Func) (Path, bool) {
+	// Concrete methods can only be declared on package-scoped named types. For
+	// that reason we can skip the expensive walk over the package scope: the
+	// path will always be package -> named type -> method. We can trivially get
+	// the type name from the receiver, and only have to look over the type's
+	// methods to find the method index.
+	//
+	// Methods on generic types require special consideration, however. Consider
+	// the following package:
+	//
+	// 	L1: type S[T any] struct{}
+	// 	L2: func (recv S[A]) Foo() { recv.Bar() }
+	// 	L3: func (recv S[B]) Bar() { }
+	// 	L4: type Alias = S[int]
+	// 	L5: func _[T any]() { var s S[int]; s.Foo() }
+	//
+	// The receivers of methods on generic types are instantiations. L2 and L3
+	// instantiate S with the type-parameters A and B, which are scoped to the
+	// respective methods. L4 and L5 each instantiate S with int. Each of these
+	// instantiations has its own method set, full of methods (and thus objects)
+	// with receivers whose types are the respective instantiations. In other
+	// words, we have
+	//
+	// S[A].Foo, S[A].Bar
+	// S[B].Foo, S[B].Bar
+	// S[int].Foo, S[int].Bar
+	//
+	// We may thus be trying to produce object paths for any of these objects.
+	//
+	// S[A].Foo and S[B].Bar are the origin methods, and their paths are S.Foo
+	// and S.Bar, which are the paths that this function naturally produces.
+	//
+	// S[A].Bar, S[B].Foo, and both methods on S[int] are instantiations that
+	// don't correspond to the origin methods. For S[int], this is significant.
+	// The most precise object path for S[int].Foo, for example, is Alias.Foo,
+	// not S.Foo. Our function, however, would produce S.Foo, which would
+	// resolve to a different object.
+	//
+	// For S[A].Bar and S[B].Foo it could be argued that S.Bar and S.Foo are
+	// still the correct paths, since only the origin methods have meaningful
+	// paths. But this is likely only true for trivial cases and has edge cases.
+	// Since this function is only an optimization, we err on the side of giving
+	// up, deferring to the slower but definitely correct algorithm. Most users
+	// of objectpath will only be giving us origin methods, anyway, as referring
+	// to instantiated methods is usually not useful.
+
+	if typeparams.OriginMethod(meth) != meth {
+		return "", false
+	}
+
+	recvT := meth.Type().(*types.Signature).Recv().Type()
+	if ptr, ok := recvT.(*types.Pointer); ok {
+		recvT = ptr.Elem()
+	}
+
+	named, ok := recvT.(*types.Named)
+	if !ok {
+		return "", false
+	}
+
+	if types.IsInterface(named) {
+		// Named interfaces don't have to be package-scoped
+		//
+		// TODO(dominikh): opt: if scope.Lookup(name) == named, then we can apply this optimization to interface
+		// methods, too, I think.
+		return "", false
+	}
+
+	// Preallocate space for the name, opType, opMethod, and some digits.
+	name := named.Obj().Name()
+	path := make([]byte, 0, len(name)+8)
+	path = append(path, name...)
+	path = append(path, opType)
+
+	if !enc.skipMethodSorting {
+		for i, m := range enc.namedMethods(named) {
+			if m == meth {
+				path = appendOpArg(path, opMethod, i)
+				return Path(path), true
+			}
+		}
+	} else {
+		// This branch must match the logic of the branch above, using go/types
+		// APIs without sorting.
+		for i := 0; i < named.NumMethods(); i++ {
+			m := named.Method(i)
+			if m == meth {
+				path = appendOpArg(path, opMethod, i)
+				return Path(path), true
+			}
+		}
+	}
+
+	// Due to golang/go#59944, go/types fails to associate the receiver with
+	// certain methods on cgo types.
+	//
+	// TODO(rfindley): replace this panic once golang/go#59944 is fixed in all Go
+	// versions gopls supports.
+	return "", false
+	// panic(fmt.Sprintf("couldn't find method %s on type %s; methods: %#v", meth, named, enc.namedMethods(named)))
+}
+
+// find finds obj within type T, returning the path to it, or nil if not found.
+//
+// The seen map is used to short circuit cycles through type parameters. If
+// nil, it will be allocated as necessary.
+func find(obj types.Object, T types.Type, path []byte, seen map[*types.TypeName]bool) []byte {
+	switch T := T.(type) {
+	case *types.Basic, *types.Named:
+		// Named types belonging to pkg were handled already,
+		// so T must belong to another package. No path.
+		return nil
+	case *types.Pointer:
+		return find(obj, T.Elem(), append(path, opElem), seen)
+	case *types.Slice:
+		return find(obj, T.Elem(), append(path, opElem), seen)
+	case *types.Array:
+		return find(obj, T.Elem(), append(path, opElem), seen)
+	case *types.Chan:
+		return find(obj, T.Elem(), append(path, opElem), seen)
+	case *types.Map:
+		if r := find(obj, T.Key(), append(path, opKey), seen); r != nil {
+			return r
+		}
+		return find(obj, T.Elem(), append(path, opElem), seen)
+	case *types.Signature:
+		if r := findTypeParam(obj, typeparams.ForSignature(T), path, seen); r != nil {
+			return r
+		}
+		if r := find(obj, T.Params(), append(path, opParams), seen); r != nil {
+			return r
+		}
+		return find(obj, T.Results(), append(path, opResults), seen)
+	case *types.Struct:
+		for i := 0; i < T.NumFields(); i++ {
+			fld := T.Field(i)
+			path2 := appendOpArg(path, opField, i)
+			if fld == obj {
+				return path2 // found field var
+			}
+			if r := find(obj, fld.Type(), append(path2, opType), seen); r != nil {
+				return r
+			}
+		}
+		return nil
+	case *types.Tuple:
+		for i := 0; i < T.Len(); i++ {
+			v := T.At(i)
+			path2 := appendOpArg(path, opAt, i)
+			if v == obj {
+				return path2 // found param/result var
+			}
+			if r := find(obj, v.Type(), append(path2, opType), seen); r != nil {
+				return r
+			}
+		}
+		return nil
+	case *types.Interface:
+		for i := 0; i < T.NumMethods(); i++ {
+			m := T.Method(i)
+			path2 := appendOpArg(path, opMethod, i)
+			if m == obj {
+				return path2 // found interface method
+			}
+			if r := find(obj, m.Type(), append(path2, opType), seen); r != nil {
+				return r
+			}
+		}
+		return nil
+	case *typeparams.TypeParam:
+		name := T.Obj()
+		if name == obj {
+			return append(path, opObj)
+		}
+		if seen[name] {
+			return nil
+		}
+		if seen == nil {
+			seen = make(map[*types.TypeName]bool)
+		}
+		seen[name] = true
+		if r := find(obj, T.Constraint(), append(path, opConstraint), seen); r != nil {
+			return r
+		}
+		return nil
+	}
+	panic(T)
+}
+
+func findTypeParam(obj types.Object, list *typeparams.TypeParamList, path []byte, seen map[*types.TypeName]bool) []byte {
+	for i := 0; i < list.Len(); i++ {
+		tparam := list.At(i)
+		path2 := appendOpArg(path, opTypeParam, i)
+		if r := find(obj, tparam, path2, seen); r != nil {
+			return r
+		}
+	}
+	return nil
+}
+
+// Object returns the object denoted by path p within the package pkg.
+func Object(pkg *types.Package, p Path) (types.Object, error) {
+	return object(pkg, string(p), false)
+}
+
+// Note: the skipMethodSorting parameter must match the value of
+// Encoder.skipMethodSorting used during encoding.
+func object(pkg *types.Package, pathstr string, skipMethodSorting bool) (types.Object, error) {
+	if pathstr == "" {
+		return nil, fmt.Errorf("empty path")
+	}
+
+	var pkgobj, suffix string
+	if dot := strings.IndexByte(pathstr, opType); dot < 0 {
+		pkgobj = pathstr
+	} else {
+		pkgobj = pathstr[:dot]
+		suffix = pathstr[dot:] // suffix starts with "."
+	}
+
+	obj := pkg.Scope().Lookup(pkgobj)
+	if obj == nil {
+		return nil, fmt.Errorf("package %s does not contain %q", pkg.Path(), pkgobj)
+	}
+
+	// abstraction of *types.{Pointer,Slice,Array,Chan,Map}
+	type hasElem interface {
+		Elem() types.Type
+	}
+	// abstraction of *types.{Named,Signature}
+	type hasTypeParams interface {
+		TypeParams() *typeparams.TypeParamList
+	}
+	// abstraction of *types.{Named,TypeParam}
+	type hasObj interface {
+		Obj() *types.TypeName
+	}
+
+	// The loop state is the pair (t, obj),
+	// exactly one of which is non-nil, initially obj.
+	// All suffixes start with '.' (the only object->type operation),
+	// followed by optional type->type operations,
+	// then a type->object operation.
+	// The cycle then repeats.
+	var t types.Type
+	for suffix != "" {
+		code := suffix[0]
+		suffix = suffix[1:]
+
+		// Codes [AFM] have an integer operand.
+		var index int
+		switch code {
+		case opAt, opField, opMethod, opTypeParam:
+			rest := strings.TrimLeft(suffix, "0123456789")
+			numerals := suffix[:len(suffix)-len(rest)]
+			suffix = rest
+			i, err := strconv.Atoi(numerals)
+			if err != nil {
+				return nil, fmt.Errorf("invalid path: bad numeric operand %q for code %q", numerals, code)
+			}
+			index = int(i)
+		case opObj:
+			// no operand
+		default:
+			// The suffix must end with a type->object operation.
+			if suffix == "" {
+				return nil, fmt.Errorf("invalid path: ends with %q, want [AFMO]", code)
+			}
+		}
+
+		if code == opType {
+			if t != nil {
+				return nil, fmt.Errorf("invalid path: unexpected %q in type context", opType)
+			}
+			t = obj.Type()
+			obj = nil
+			continue
+		}
+
+		if t == nil {
+			return nil, fmt.Errorf("invalid path: code %q in object context", code)
+		}
+
+		// Inv: t != nil, obj == nil
+
+		switch code {
+		case opElem:
+			hasElem, ok := t.(hasElem) // Pointer, Slice, Array, Chan, Map
+			if !ok {
+				return nil, fmt.Errorf("cannot apply %q to %s (got %T, want pointer, slice, array, chan or map)", code, t, t)
+			}
+			t = hasElem.Elem()
+
+		case opKey:
+			mapType, ok := t.(*types.Map)
+			if !ok {
+				return nil, fmt.Errorf("cannot apply %q to %s (got %T, want map)", code, t, t)
+			}
+			t = mapType.Key()
+
+		case opParams:
+			sig, ok := t.(*types.Signature)
+			if !ok {
+				return nil, fmt.Errorf("cannot apply %q to %s (got %T, want signature)", code, t, t)
+			}
+			t = sig.Params()
+
+		case opResults:
+			sig, ok := t.(*types.Signature)
+			if !ok {
+				return nil, fmt.Errorf("cannot apply %q to %s (got %T, want signature)", code, t, t)
+			}
+			t = sig.Results()
+
+		case opUnderlying:
+			named, ok := t.(*types.Named)
+			if !ok {
+				return nil, fmt.Errorf("cannot apply %q to %s (got %T, want named)", code, t, t)
+			}
+			t = named.Underlying()
+
+		case opTypeParam:
+			hasTypeParams, ok := t.(hasTypeParams) // Named, Signature
+			if !ok {
+				return nil, fmt.Errorf("cannot apply %q to %s (got %T, want named or signature)", code, t, t)
+			}
+			tparams := hasTypeParams.TypeParams()
+			if n := tparams.Len(); index >= n {
+				return nil, fmt.Errorf("tuple index %d out of range [0-%d)", index, n)
+			}
+			t = tparams.At(index)
+
+		case opConstraint:
+			tparam, ok := t.(*typeparams.TypeParam)
+			if !ok {
+				return nil, fmt.Errorf("cannot apply %q to %s (got %T, want type parameter)", code, t, t)
+			}
+			t = tparam.Constraint()
+
+		case opAt:
+			tuple, ok := t.(*types.Tuple)
+			if !ok {
+				return nil, fmt.Errorf("cannot apply %q to %s (got %T, want tuple)", code, t, t)
+			}
+			if n := tuple.Len(); index >= n {
+				return nil, fmt.Errorf("tuple index %d out of range [0-%d)", index, n)
+			}
+			obj = tuple.At(index)
+			t = nil
+
+		case opField:
+			structType, ok := t.(*types.Struct)
+			if !ok {
+				return nil, fmt.Errorf("cannot apply %q to %s (got %T, want struct)", code, t, t)
+			}
+			if n := structType.NumFields(); index >= n {
+				return nil, fmt.Errorf("field index %d out of range [0-%d)", index, n)
+			}
+			obj = structType.Field(index)
+			t = nil
+
+		case opMethod:
+			switch t := t.(type) {
+			case *types.Interface:
+				if index >= t.NumMethods() {
+					return nil, fmt.Errorf("method index %d out of range [0-%d)", index, t.NumMethods())
+				}
+				obj = t.Method(index) // Id-ordered
+
+			case *types.Named:
+				if index >= t.NumMethods() {
+					return nil, fmt.Errorf("method index %d out of range [0-%d)", index, t.NumMethods())
+				}
+				if skipMethodSorting {
+					obj = t.Method(index)
+				} else {
+					methods := namedMethods(t) // (unmemoized)
+					obj = methods[index]       // Id-ordered
+				}
+
+			default:
+				return nil, fmt.Errorf("cannot apply %q to %s (got %T, want interface or named)", code, t, t)
+			}
+			t = nil
+
+		case opObj:
+			hasObj, ok := t.(hasObj)
+			if !ok {
+				return nil, fmt.Errorf("cannot apply %q to %s (got %T, want named or type param)", code, t, t)
+			}
+			obj = hasObj.Obj()
+			t = nil
+
+		default:
+			return nil, fmt.Errorf("invalid path: unknown code %q", code)
+		}
+	}
+
+	if obj.Pkg() != pkg {
+		return nil, fmt.Errorf("path denotes %s, which belongs to a different package", obj)
+	}
+
+	return obj, nil // success
+}
+
+// namedMethods returns the methods of a Named type in ascending Id order.
+func namedMethods(named *types.Named) []*types.Func {
+	methods := make([]*types.Func, named.NumMethods())
+	for i := range methods {
+		methods[i] = named.Method(i)
+	}
+	sort.Slice(methods, func(i, j int) bool {
+		return methods[i].Id() < methods[j].Id()
+	})
+	return methods
+}
+
+// namedMethods is a memoization of the namedMethods function. Callers must not modify the result.
+func (enc *Encoder) namedMethods(named *types.Named) []*types.Func {
+	m := enc.namedMethodsMemo
+	if m == nil {
+		m = make(map[*types.Named][]*types.Func)
+		enc.namedMethodsMemo = m
+	}
+	methods, ok := m[named]
+	if !ok {
+		methods = namedMethods(named) // allocates and sorts
+		m[named] = methods
+	}
+	return methods
+}
+
+// scopeObjects is a memoization of scope objects.
+// Callers must not modify the result.
+func (enc *Encoder) scopeObjects(scope *types.Scope) []types.Object {
+	m := enc.scopeMemo
+	if m == nil {
+		m = make(map[*types.Scope][]types.Object)
+		enc.scopeMemo = m
+	}
+	objs, ok := m[scope]
+	if !ok {
+		names := scope.Names() // allocates and sorts
+		objs = make([]types.Object, len(names))
+		for i, name := range names {
+			objs[i] = scope.Lookup(name)
+		}
+		m[scope] = objs
+	}
+	return objs
+}

vendor/golang.org/x/tools/internal/event/tag/tag.go

@@ -0,0 +1,59 @@
+// Copyright 2019 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+// Package tag provides the labels used for telemetry throughout gopls.
+package tag
+
+import (
+	"golang.org/x/tools/internal/event/keys"
+)
+
+var (
+	// create the label keys we use
+	Method        = keys.NewString("method", "")
+	StatusCode    = keys.NewString("status.code", "")
+	StatusMessage = keys.NewString("status.message", "")
+	RPCID         = keys.NewString("id", "")
+	RPCDirection  = keys.NewString("direction", "")
+	File          = keys.NewString("file", "")
+	Directory     = keys.New("directory", "")
+	URI           = keys.New("URI", "")
+	Package       = keys.NewString("package", "") // sorted comma-separated list of Package IDs
+	PackagePath   = keys.NewString("package_path", "")
+	Query         = keys.New("query", "")
+	Snapshot      = keys.NewUInt64("snapshot", "")
+	Operation     = keys.NewString("operation", "")
+
+	Position     = keys.New("position", "")
+	Category     = keys.NewString("category", "")
+	PackageCount = keys.NewInt("packages", "")
+	Files        = keys.New("files", "")
+	Port         = keys.NewInt("port", "")
+	Type         = keys.New("type", "")
+	HoverKind    = keys.NewString("hoverkind", "")
+
+	NewServer = keys.NewString("new_server", "A new server was added")
+	EndServer = keys.NewString("end_server", "A server was shut down")
+
+	ServerID     = keys.NewString("server", "The server ID an event is related to")
+	Logfile      = keys.NewString("logfile", "")
+	DebugAddress = keys.NewString("debug_address", "")
+	GoplsPath    = keys.NewString("gopls_path", "")
+	ClientID     = keys.NewString("client_id", "")
+
+	Level = keys.NewInt("level", "The logging level")
+)
+
+var (
+	// create the stats we measure
+	Started       = keys.NewInt64("started", "Count of started RPCs.")
+	ReceivedBytes = keys.NewInt64("received_bytes", "Bytes received.")            //, unit.Bytes)
+	SentBytes     = keys.NewInt64("sent_bytes", "Bytes sent.")                    //, unit.Bytes)
+	Latency       = keys.NewFloat64("latency_ms", "Elapsed time in milliseconds") //, unit.Milliseconds)
+)
+
+const (
+	Inbound  = "in"
+	Outbound = "out"
+)

vendor/golang.org/x/tools/internal/gcimporter/bexport.go

@@ -1,852 +0,0 @@
-// Copyright 2016 The Go Authors. All rights reserved.
-// Use of this source code is governed by a BSD-style
-// license that can be found in the LICENSE file.
-
-// Binary package export.
-// This file was derived from $GOROOT/src/cmd/compile/internal/gc/bexport.go;
-// see that file for specification of the format.
-
-package gcimporter
-
-import (
-	"bytes"
-	"encoding/binary"
-	"fmt"
-	"go/constant"
-	"go/token"
-	"go/types"
-	"math"
-	"math/big"
-	"sort"
-	"strings"
-)
-
-// If debugFormat is set, each integer and string value is preceded by a marker
-// and position information in the encoding. This mechanism permits an importer
-// to recognize immediately when it is out of sync. The importer recognizes this
-// mode automatically (i.e., it can import export data produced with debugging
-// support even if debugFormat is not set at the time of import). This mode will
-// lead to massively larger export data (by a factor of 2 to 3) and should only
-// be enabled during development and debugging.
-//
-// NOTE: This flag is the first flag to enable if importing dies because of
-// (suspected) format errors, and whenever a change is made to the format.
-const debugFormat = false // default: false
-
-// Current export format version. Increase with each format change.
-//
-// Note: The latest binary (non-indexed) export format is at version 6.
-// This exporter is still at level 4, but it doesn't matter since
-// the binary importer can handle older versions just fine.
-//
-//	6: package height (CL 105038) -- NOT IMPLEMENTED HERE
-//	5: improved position encoding efficiency (issue 20080, CL 41619) -- NOT IMPLEMENTED HERE
-//	4: type name objects support type aliases, uses aliasTag
-//	3: Go1.8 encoding (same as version 2, aliasTag defined but never used)
-//	2: removed unused bool in ODCL export (compiler only)
-//	1: header format change (more regular), export package for _ struct fields
-//	0: Go1.7 encoding
-const exportVersion = 4
-
-// trackAllTypes enables cycle tracking for all types, not just named
-// types. The existing compiler invariants assume that unnamed types
-// that are not completely set up are not used, or else there are spurious
-// errors.
-// If disabled, only named types are tracked, possibly leading to slightly
-// less efficient encoding in rare cases. It also prevents the export of
-// some corner-case type declarations (but those are not handled correctly
-// with with the textual export format either).
-// TODO(gri) enable and remove once issues caused by it are fixed
-const trackAllTypes = false
-
-type exporter struct {
-	fset *token.FileSet
-	out  bytes.Buffer
-
-	// object -> index maps, indexed in order of serialization
-	strIndex map[string]int
-	pkgIndex map[*types.Package]int
-	typIndex map[types.Type]int
-
-	// position encoding
-	posInfoFormat bool
-	prevFile      string
-	prevLine      int
-
-	// debugging support
-	written int // bytes written
-	indent  int // for trace
-}
-
-// internalError represents an error generated inside this package.
-type internalError string
-
-func (e internalError) Error() string { return "gcimporter: " + string(e) }
-
-func internalErrorf(format string, args ...interface{}) error {
-	return internalError(fmt.Sprintf(format, args...))
-}
-
-// BExportData returns binary export data for pkg.
-// If no file set is provided, position info will be missing.
-func BExportData(fset *token.FileSet, pkg *types.Package) (b []byte, err error) {
-	if !debug {
-		defer func() {
-			if e := recover(); e != nil {
-				if ierr, ok := e.(internalError); ok {
-					err = ierr
-					return
-				}
-				// Not an internal error; panic again.
-				panic(e)
-			}
-		}()
-	}
-
-	p := exporter{
-		fset:          fset,
-		strIndex:      map[string]int{"": 0}, // empty string is mapped to 0
-		pkgIndex:      make(map[*types.Package]int),
-		typIndex:      make(map[types.Type]int),
-		posInfoFormat: true, // TODO(gri) might become a flag, eventually
-	}
-
-	// write version info
-	// The version string must start with "version %d" where %d is the version
-	// number. Additional debugging information may follow after a blank; that
-	// text is ignored by the importer.
-	p.rawStringln(fmt.Sprintf("version %d", exportVersion))
-	var debug string
-	if debugFormat {
-		debug = "debug"
-	}
-	p.rawStringln(debug) // cannot use p.bool since it's affected by debugFormat; also want to see this clearly
-	p.bool(trackAllTypes)
-	p.bool(p.posInfoFormat)
-
-	// --- generic export data ---
-
-	// populate type map with predeclared "known" types
-	for index, typ := range predeclared() {
-		p.typIndex[typ] = index
-	}
-	if len(p.typIndex) != len(predeclared()) {
-		return nil, internalError("duplicate entries in type map?")
-	}
-
-	// write package data
-	p.pkg(pkg, true)
-	if trace {
-		p.tracef("\n")
-	}
-
-	// write objects
-	objcount := 0
-	scope := pkg.Scope()
-	for _, name := range scope.Names() {
-		if !token.IsExported(name) {
-			continue
-		}
-		if trace {
-			p.tracef("\n")
-		}
-		p.obj(scope.Lookup(name))
-		objcount++
-	}
-
-	// indicate end of list
-	if trace {
-		p.tracef("\n")
-	}
-	p.tag(endTag)
-
-	// for self-verification only (redundant)
-	p.int(objcount)
-
-	if trace {
-		p.tracef("\n")
-	}
-
-	// --- end of export data ---
-
-	return p.out.Bytes(), nil
-}
-
-func (p *exporter) pkg(pkg *types.Package, emptypath bool) {
-	if pkg == nil {
-		panic(internalError("unexpected nil pkg"))
-	}
-
-	// if we saw the package before, write its index (>= 0)
-	if i, ok := p.pkgIndex[pkg]; ok {
-		p.index('P', i)
-		return
-	}
-
-	// otherwise, remember the package, write the package tag (< 0) and package data
-	if trace {
-		p.tracef("P%d = { ", len(p.pkgIndex))
-		defer p.tracef("} ")
-	}
-	p.pkgIndex[pkg] = len(p.pkgIndex)
-
-	p.tag(packageTag)
-	p.string(pkg.Name())
-	if emptypath {
-		p.string("")
-	} else {
-		p.string(pkg.Path())
-	}
-}
-
-func (p *exporter) obj(obj types.Object) {
-	switch obj := obj.(type) {
-	case *types.Const:
-		p.tag(constTag)
-		p.pos(obj)
-		p.qualifiedName(obj)
-		p.typ(obj.Type())
-		p.value(obj.Val())
-
-	case *types.TypeName:
-		if obj.IsAlias() {
-			p.tag(aliasTag)
-			p.pos(obj)
-			p.qualifiedName(obj)
-		} else {
-			p.tag(typeTag)
-		}
-		p.typ(obj.Type())
-
-	case *types.Var:
-		p.tag(varTag)
-		p.pos(obj)
-		p.qualifiedName(obj)
-		p.typ(obj.Type())
-
-	case *types.Func:
-		p.tag(funcTag)
-		p.pos(obj)
-		p.qualifiedName(obj)
-		sig := obj.Type().(*types.Signature)
-		p.paramList(sig.Params(), sig.Variadic())
-		p.paramList(sig.Results(), false)
-
-	default:
-		panic(internalErrorf("unexpected object %v (%T)", obj, obj))
-	}
-}
-
-func (p *exporter) pos(obj types.Object) {
-	if !p.posInfoFormat {
-		return
-	}
-
-	file, line := p.fileLine(obj)
-	if file == p.prevFile {
-		// common case: write line delta
-		// delta == 0 means different file or no line change
-		delta := line - p.prevLine
-		p.int(delta)
-		if delta == 0 {
-			p.int(-1) // -1 means no file change
-		}
-	} else {
-		// different file
-		p.int(0)
-		// Encode filename as length of common prefix with previous
-		// filename, followed by (possibly empty) suffix. Filenames
-		// frequently share path prefixes, so this can save a lot
-		// of space and make export data size less dependent on file
-		// path length. The suffix is unlikely to be empty because
-		// file names tend to end in ".go".
-		n := commonPrefixLen(p.prevFile, file)
-		p.int(n)           // n >= 0
-		p.string(file[n:]) // write suffix only
-		p.prevFile = file
-		p.int(line)
-	}
-	p.prevLine = line
-}
-
-func (p *exporter) fileLine(obj types.Object) (file string, line int) {
-	if p.fset != nil {
-		pos := p.fset.Position(obj.Pos())
-		file = pos.Filename
-		line = pos.Line
-	}
-	return
-}
-
-func commonPrefixLen(a, b string) int {
-	if len(a) > len(b) {
-		a, b = b, a
-	}
-	// len(a) <= len(b)
-	i := 0
-	for i < len(a) && a[i] == b[i] {
-		i++
-	}
-	return i
-}
-
-func (p *exporter) qualifiedName(obj types.Object) {
-	p.string(obj.Name())
-	p.pkg(obj.Pkg(), false)
-}
-
-func (p *exporter) typ(t types.Type) {
-	if t == nil {
-		panic(internalError("nil type"))
-	}
-
-	// Possible optimization: Anonymous pointer types *T where
-	// T is a named type are common. We could canonicalize all
-	// such types *T to a single type PT = *T. This would lead
-	// to at most one *T entry in typIndex, and all future *T's
-	// would be encoded as the respective index directly. Would
-	// save 1 byte (pointerTag) per *T and reduce the typIndex
-	// size (at the cost of a canonicalization map). We can do
-	// this later, without encoding format change.
-
-	// if we saw the type before, write its index (>= 0)
-	if i, ok := p.typIndex[t]; ok {
-		p.index('T', i)
-		return
-	}
-
-	// otherwise, remember the type, write the type tag (< 0) and type data
-	if trackAllTypes {
-		if trace {
-			p.tracef("T%d = {>\n", len(p.typIndex))
-			defer p.tracef("<\n} ")
-		}
-		p.typIndex[t] = len(p.typIndex)
-	}
-
-	switch t := t.(type) {
-	case *types.Named:
-		if !trackAllTypes {
-			// if we don't track all types, track named types now
-			p.typIndex[t] = len(p.typIndex)
-		}
-
-		p.tag(namedTag)
-		p.pos(t.Obj())
-		p.qualifiedName(t.Obj())
-		p.typ(t.Underlying())
-		if !types.IsInterface(t) {
-			p.assocMethods(t)
-		}
-
-	case *types.Array:
-		p.tag(arrayTag)
-		p.int64(t.Len())
-		p.typ(t.Elem())
-
-	case *types.Slice:
-		p.tag(sliceTag)
-		p.typ(t.Elem())
-
-	case *dddSlice:
-		p.tag(dddTag)
-		p.typ(t.elem)
-
-	case *types.Struct:
-		p.tag(structTag)
-		p.fieldList(t)
-
-	case *types.Pointer:
-		p.tag(pointerTag)
-		p.typ(t.Elem())
-
-	case *types.Signature:
-		p.tag(signatureTag)
-		p.paramList(t.Params(), t.Variadic())
-		p.paramList(t.Results(), false)
-
-	case *types.Interface:
-		p.tag(interfaceTag)
-		p.iface(t)
-
-	case *types.Map:
-		p.tag(mapTag)
-		p.typ(t.Key())
-		p.typ(t.Elem())
-
-	case *types.Chan:
-		p.tag(chanTag)
-		p.int(int(3 - t.Dir())) // hack
-		p.typ(t.Elem())
-
-	default:
-		panic(internalErrorf("unexpected type %T: %s", t, t))
-	}
-}
-
-func (p *exporter) assocMethods(named *types.Named) {
-	// Sort methods (for determinism).
-	var methods []*types.Func
-	for i := 0; i < named.NumMethods(); i++ {
-		methods = append(methods, named.Method(i))
-	}
-	sort.Sort(methodsByName(methods))
-
-	p.int(len(methods))
-
-	if trace && methods != nil {
-		p.tracef("associated methods {>\n")
-	}
-
-	for i, m := range methods {
-		if trace && i > 0 {
-			p.tracef("\n")
-		}
-
-		p.pos(m)
-		name := m.Name()
-		p.string(name)
-		if !exported(name) {
-			p.pkg(m.Pkg(), false)
-		}
-
-		sig := m.Type().(*types.Signature)
-		p.paramList(types.NewTuple(sig.Recv()), false)
-		p.paramList(sig.Params(), sig.Variadic())
-		p.paramList(sig.Results(), false)
-		p.int(0) // dummy value for go:nointerface pragma - ignored by importer
-	}
-
-	if trace && methods != nil {
-		p.tracef("<\n} ")
-	}
-}
-
-type methodsByName []*types.Func
-
-func (x methodsByName) Len() int           { return len(x) }
-func (x methodsByName) Swap(i, j int)      { x[i], x[j] = x[j], x[i] }
-func (x methodsByName) Less(i, j int) bool { return x[i].Name() < x[j].Name() }
-
-func (p *exporter) fieldList(t *types.Struct) {
-	if trace && t.NumFields() > 0 {
-		p.tracef("fields {>\n")
-		defer p.tracef("<\n} ")
-	}
-
-	p.int(t.NumFields())
-	for i := 0; i < t.NumFields(); i++ {
-		if trace && i > 0 {
-			p.tracef("\n")
-		}
-		p.field(t.Field(i))
-		p.string(t.Tag(i))
-	}
-}
-
-func (p *exporter) field(f *types.Var) {
-	if !f.IsField() {
-		panic(internalError("field expected"))
-	}
-
-	p.pos(f)
-	p.fieldName(f)
-	p.typ(f.Type())
-}
-
-func (p *exporter) iface(t *types.Interface) {
-	// TODO(gri): enable importer to load embedded interfaces,
-	// then emit Embeddeds and ExplicitMethods separately here.
-	p.int(0)
-
-	n := t.NumMethods()
-	if trace && n > 0 {
-		p.tracef("methods {>\n")
-		defer p.tracef("<\n} ")
-	}
-	p.int(n)
-	for i := 0; i < n; i++ {
-		if trace && i > 0 {
-			p.tracef("\n")
-		}
-		p.method(t.Method(i))
-	}
-}
-
-func (p *exporter) method(m *types.Func) {
-	sig := m.Type().(*types.Signature)
-	if sig.Recv() == nil {
-		panic(internalError("method expected"))
-	}
-
-	p.pos(m)
-	p.string(m.Name())
-	if m.Name() != "_" && !token.IsExported(m.Name()) {
-		p.pkg(m.Pkg(), false)
-	}
-
-	// interface method; no need to encode receiver.
-	p.paramList(sig.Params(), sig.Variadic())
-	p.paramList(sig.Results(), false)
-}
-
-func (p *exporter) fieldName(f *types.Var) {
-	name := f.Name()
-
-	if f.Anonymous() {
-		// anonymous field - we distinguish between 3 cases:
-		// 1) field name matches base type name and is exported
-		// 2) field name matches base type name and is not exported
-		// 3) field name doesn't match base type name (alias name)
-		bname := basetypeName(f.Type())
-		if name == bname {
-			if token.IsExported(name) {
-				name = "" // 1) we don't need to know the field name or package
-			} else {
-				name = "?" // 2) use unexported name "?" to force package export
-			}
-		} else {
-			// 3) indicate alias and export name as is
-			// (this requires an extra "@" but this is a rare case)
-			p.string("@")
-		}
-	}
-
-	p.string(name)
-	if name != "" && !token.IsExported(name) {
-		p.pkg(f.Pkg(), false)
-	}
-}
-
-func basetypeName(typ types.Type) string {
-	switch typ := deref(typ).(type) {
-	case *types.Basic:
-		return typ.Name()
-	case *types.Named:
-		return typ.Obj().Name()
-	default:
-		return "" // unnamed type
-	}
-}
-
-func (p *exporter) paramList(params *types.Tuple, variadic bool) {
-	// use negative length to indicate unnamed parameters
-	// (look at the first parameter only since either all
-	// names are present or all are absent)
-	n := params.Len()
-	if n > 0 && params.At(0).Name() == "" {
-		n = -n
-	}
-	p.int(n)
-	for i := 0; i < params.Len(); i++ {
-		q := params.At(i)
-		t := q.Type()
-		if variadic && i == params.Len()-1 {
-			t = &dddSlice{t.(*types.Slice).Elem()}
-		}
-		p.typ(t)
-		if n > 0 {
-			name := q.Name()
-			p.string(name)
-			if name != "_" {
-				p.pkg(q.Pkg(), false)
-			}
-		}
-		p.string("") // no compiler-specific info
-	}
-}
-
-func (p *exporter) value(x constant.Value) {
-	if trace {
-		p.tracef("= ")
-	}
-
-	switch x.Kind() {
-	case constant.Bool:
-		tag := falseTag
-		if constant.BoolVal(x) {
-			tag = trueTag
-		}
-		p.tag(tag)
-
-	case constant.Int:
-		if v, exact := constant.Int64Val(x); exact {
-			// common case: x fits into an int64 - use compact encoding
-			p.tag(int64Tag)
-			p.int64(v)
-			return
-		}
-		// uncommon case: large x - use float encoding
-		// (powers of 2 will be encoded efficiently with exponent)
-		p.tag(floatTag)
-		p.float(constant.ToFloat(x))
-
-	case constant.Float:
-		p.tag(floatTag)
-		p.float(x)
-
-	case constant.Complex:
-		p.tag(complexTag)
-		p.float(constant.Real(x))
-		p.float(constant.Imag(x))
-
-	case constant.String:
-		p.tag(stringTag)
-		p.string(constant.StringVal(x))
-
-	case constant.Unknown:
-		// package contains type errors
-		p.tag(unknownTag)
-
-	default:
-		panic(internalErrorf("unexpected value %v (%T)", x, x))
-	}
-}
-
-func (p *exporter) float(x constant.Value) {
-	if x.Kind() != constant.Float {
-		panic(internalErrorf("unexpected constant %v, want float", x))
-	}
-	// extract sign (there is no -0)
-	sign := constant.Sign(x)
-	if sign == 0 {
-		// x == 0
-		p.int(0)
-		return
-	}
-	// x != 0
-
-	var f big.Float
-	if v, exact := constant.Float64Val(x); exact {
-		// float64
-		f.SetFloat64(v)
-	} else if num, denom := constant.Num(x), constant.Denom(x); num.Kind() == constant.Int {
-		// TODO(gri): add big.Rat accessor to constant.Value.
-		r := valueToRat(num)
-		f.SetRat(r.Quo(r, valueToRat(denom)))
-	} else {
-		// Value too large to represent as a fraction => inaccessible.
-		// TODO(gri): add big.Float accessor to constant.Value.
-		f.SetFloat64(math.MaxFloat64) // FIXME
-	}
-
-	// extract exponent such that 0.5 <= m < 1.0
-	var m big.Float
-	exp := f.MantExp(&m)
-
-	// extract mantissa as *big.Int
-	// - set exponent large enough so mant satisfies mant.IsInt()
-	// - get *big.Int from mant
-	m.SetMantExp(&m, int(m.MinPrec()))
-	mant, acc := m.Int(nil)
-	if acc != big.Exact {
-		panic(internalError("internal error"))
-	}
-
-	p.int(sign)
-	p.int(exp)
-	p.string(string(mant.Bytes()))
-}
-
-func valueToRat(x constant.Value) *big.Rat {
-	// Convert little-endian to big-endian.
-	// I can't believe this is necessary.
-	bytes := constant.Bytes(x)
-	for i := 0; i < len(bytes)/2; i++ {
-		bytes[i], bytes[len(bytes)-1-i] = bytes[len(bytes)-1-i], bytes[i]
-	}
-	return new(big.Rat).SetInt(new(big.Int).SetBytes(bytes))
-}
-
-func (p *exporter) bool(b bool) bool {
-	if trace {
-		p.tracef("[")
-		defer p.tracef("= %v] ", b)
-	}
-
-	x := 0
-	if b {
-		x = 1
-	}
-	p.int(x)
-	return b
-}
-
-// ----------------------------------------------------------------------------
-// Low-level encoders
-
-func (p *exporter) index(marker byte, index int) {
-	if index < 0 {
-		panic(internalError("invalid index < 0"))
-	}
-	if debugFormat {
-		p.marker('t')
-	}
-	if trace {
-		p.tracef("%c%d ", marker, index)
-	}
-	p.rawInt64(int64(index))
-}
-
-func (p *exporter) tag(tag int) {
-	if tag >= 0 {
-		panic(internalError("invalid tag >= 0"))
-	}
-	if debugFormat {
-		p.marker('t')
-	}
-	if trace {
-		p.tracef("%s ", tagString[-tag])
-	}
-	p.rawInt64(int64(tag))
-}
-
-func (p *exporter) int(x int) {
-	p.int64(int64(x))
-}
-
-func (p *exporter) int64(x int64) {
-	if debugFormat {
-		p.marker('i')
-	}
-	if trace {
-		p.tracef("%d ", x)
-	}
-	p.rawInt64(x)
-}
-
-func (p *exporter) string(s string) {
-	if debugFormat {
-		p.marker('s')
-	}
-	if trace {
-		p.tracef("%q ", s)
-	}
-	// if we saw the string before, write its index (>= 0)
-	// (the empty string is mapped to 0)
-	if i, ok := p.strIndex[s]; ok {
-		p.rawInt64(int64(i))
-		return
-	}
-	// otherwise, remember string and write its negative length and bytes
-	p.strIndex[s] = len(p.strIndex)
-	p.rawInt64(-int64(len(s)))
-	for i := 0; i < len(s); i++ {
-		p.rawByte(s[i])
-	}
-}
-
-// marker emits a marker byte and position information which makes
-// it easy for a reader to detect if it is "out of sync". Used for
-// debugFormat format only.
-func (p *exporter) marker(m byte) {
-	p.rawByte(m)
-	// Enable this for help tracking down the location
-	// of an incorrect marker when running in debugFormat.
-	if false && trace {
-		p.tracef("#%d ", p.written)
-	}
-	p.rawInt64(int64(p.written))
-}
-
-// rawInt64 should only be used by low-level encoders.
-func (p *exporter) rawInt64(x int64) {
-	var tmp [binary.MaxVarintLen64]byte
-	n := binary.PutVarint(tmp[:], x)
-	for i := 0; i < n; i++ {
-		p.rawByte(tmp[i])
-	}
-}
-
-// rawStringln should only be used to emit the initial version string.
-func (p *exporter) rawStringln(s string) {
-	for i := 0; i < len(s); i++ {
-		p.rawByte(s[i])
-	}
-	p.rawByte('\n')
-}
-
-// rawByte is the bottleneck interface to write to p.out.
-// rawByte escapes b as follows (any encoding does that
-// hides '$'):
-//
-//	'$'  => '|' 'S'
-//	'|'  => '|' '|'
-//
-// Necessary so other tools can find the end of the
-// export data by searching for "$$".
-// rawByte should only be used by low-level encoders.
-func (p *exporter) rawByte(b byte) {
-	switch b {
-	case '$':
-		// write '$' as '|' 'S'
-		b = 'S'
-		fallthrough
-	case '|':
-		// write '|' as '|' '|'
-		p.out.WriteByte('|')
-		p.written++
-	}
-	p.out.WriteByte(b)
-	p.written++
-}
-
-// tracef is like fmt.Printf but it rewrites the format string
-// to take care of indentation.
-func (p *exporter) tracef(format string, args ...interface{}) {
-	if strings.ContainsAny(format, "<>\n") {
-		var buf bytes.Buffer
-		for i := 0; i < len(format); i++ {
-			// no need to deal with runes
-			ch := format[i]
-			switch ch {
-			case '>':
-				p.indent++
-				continue
-			case '<':
-				p.indent--
-				continue
-			}
-			buf.WriteByte(ch)
-			if ch == '\n' {
-				for j := p.indent; j > 0; j-- {
-					buf.WriteString(".  ")
-				}
-			}
-		}
-		format = buf.String()
-	}
-	fmt.Printf(format, args...)
-}
-
-// Debugging support.
-// (tagString is only used when tracing is enabled)
-var tagString = [...]string{
-	// Packages
-	-packageTag: "package",
-
-	// Types
-	-namedTag:     "named type",
-	-arrayTag:     "array",
-	-sliceTag:     "slice",
-	-dddTag:       "ddd",
-	-structTag:    "struct",
-	-pointerTag:   "pointer",
-	-signatureTag: "signature",
-	-interfaceTag: "interface",
-	-mapTag:       "map",
-	-chanTag:      "chan",
-
-	// Values
-	-falseTag:    "false",
-	-trueTag:     "true",
-	-int64Tag:    "int64",
-	-floatTag:    "float",
-	-fractionTag: "fraction",
-	-complexTag:  "complex",
-	-stringTag:   "string",
-	-unknownTag:  "unknown",
-
-	// Type aliases
-	-aliasTag: "alias",
-}

vendor/golang.org/x/tools/internal/gcimporter/bimport.go

@@ -2,340 +2,24 @@
 // Use of this source code is governed by a BSD-style
 // license that can be found in the LICENSE file.
 
-// This file is a copy of $GOROOT/src/go/internal/gcimporter/bimport.go.
+// This file contains the remaining vestiges of
+// $GOROOT/src/go/internal/gcimporter/bimport.go.
 
 package gcimporter
 
 import (
-	"encoding/binary"
 	"fmt"
-	"go/constant"
 	"go/token"
 	"go/types"
-	"sort"
-	"strconv"
-	"strings"
 	"sync"
-	"unicode"
-	"unicode/utf8"
 )
 
-type importer struct {
-	imports    map[string]*types.Package
-	data       []byte
-	importpath string
-	buf        []byte // for reading strings
-	version    int    // export format version
-
-	// object lists
-	strList       []string           // in order of appearance
-	pathList      []string           // in order of appearance
-	pkgList       []*types.Package   // in order of appearance
-	typList       []types.Type       // in order of appearance
-	interfaceList []*types.Interface // for delayed completion only
-	trackAllTypes bool
-
-	// position encoding
-	posInfoFormat bool
-	prevFile      string
-	prevLine      int
-	fake          fakeFileSet
-
-	// debugging support
-	debugFormat bool
-	read        int // bytes read
-}
-
-// BImportData imports a package from the serialized package data
-// and returns the number of bytes consumed and a reference to the package.
-// If the export data version is not recognized or the format is otherwise
-// compromised, an error is returned.
-func BImportData(fset *token.FileSet, imports map[string]*types.Package, data []byte, path string) (_ int, pkg *types.Package, err error) {
-	// catch panics and return them as errors
-	const currentVersion = 6
-	version := -1 // unknown version
-	defer func() {
-		if e := recover(); e != nil {
-			// Return a (possibly nil or incomplete) package unchanged (see #16088).
-			if version > currentVersion {
-				err = fmt.Errorf("cannot import %q (%v), export data is newer version - update tool", path, e)
-			} else {
-				err = fmt.Errorf("cannot import %q (%v), possibly version skew - reinstall package", path, e)
-			}
-		}
-	}()
-
-	p := importer{
-		imports:    imports,
-		data:       data,
-		importpath: path,
-		version:    version,
-		strList:    []string{""}, // empty string is mapped to 0
-		pathList:   []string{""}, // empty string is mapped to 0
-		fake: fakeFileSet{
-			fset:  fset,
-			files: make(map[string]*fileInfo),
-		},
-	}
-	defer p.fake.setLines() // set lines for files in fset
-
-	// read version info
-	var versionstr string
-	if b := p.rawByte(); b == 'c' || b == 'd' {
-		// Go1.7 encoding; first byte encodes low-level
-		// encoding format (compact vs debug).
-		// For backward-compatibility only (avoid problems with
-		// old installed packages). Newly compiled packages use
-		// the extensible format string.
-		// TODO(gri) Remove this support eventually; after Go1.8.
-		if b == 'd' {
-			p.debugFormat = true
-		}
-		p.trackAllTypes = p.rawByte() == 'a'
-		p.posInfoFormat = p.int() != 0
-		versionstr = p.string()
-		if versionstr == "v1" {
-			version = 0
-		}
-	} else {
-		// Go1.8 extensible encoding
-		// read version string and extract version number (ignore anything after the version number)
-		versionstr = p.rawStringln(b)
-		if s := strings.SplitN(versionstr, " ", 3); len(s) >= 2 && s[0] == "version" {
-			if v, err := strconv.Atoi(s[1]); err == nil && v > 0 {
-				version = v
-			}
-		}
-	}
-	p.version = version
-
-	// read version specific flags - extend as necessary
-	switch p.version {
-	// case currentVersion:
-	// 	...
-	//	fallthrough
-	case currentVersion, 5, 4, 3, 2, 1:
-		p.debugFormat = p.rawStringln(p.rawByte()) == "debug"
-		p.trackAllTypes = p.int() != 0
-		p.posInfoFormat = p.int() != 0
-	case 0:
-		// Go1.7 encoding format - nothing to do here
-	default:
-		errorf("unknown bexport format version %d (%q)", p.version, versionstr)
-	}
-
-	// --- generic export data ---
-
-	// populate typList with predeclared "known" types
-	p.typList = append(p.typList, predeclared()...)
-
-	// read package data
-	pkg = p.pkg()
-
-	// read objects of phase 1 only (see cmd/compile/internal/gc/bexport.go)
-	objcount := 0
-	for {
-		tag := p.tagOrIndex()
-		if tag == endTag {
-			break
-		}
-		p.obj(tag)
-		objcount++
-	}
-
-	// self-verification
-	if count := p.int(); count != objcount {
-		errorf("got %d objects; want %d", objcount, count)
-	}
-
-	// ignore compiler-specific import data
-
-	// complete interfaces
-	// TODO(gri) re-investigate if we still need to do this in a delayed fashion
-	for _, typ := range p.interfaceList {
-		typ.Complete()
-	}
-
-	// record all referenced packages as imports
-	list := append(([]*types.Package)(nil), p.pkgList[1:]...)
-	sort.Sort(byPath(list))
-	pkg.SetImports(list)
-
-	// package was imported completely and without errors
-	pkg.MarkComplete()
-
-	return p.read, pkg, nil
-}
-
 func errorf(format string, args ...interface{}) {
 	panic(fmt.Sprintf(format, args...))
 }
 
-func (p *importer) pkg() *types.Package {
-	// if the package was seen before, i is its index (>= 0)
-	i := p.tagOrIndex()
-	if i >= 0 {
-		return p.pkgList[i]
-	}
-
-	// otherwise, i is the package tag (< 0)
-	if i != packageTag {
-		errorf("unexpected package tag %d version %d", i, p.version)
-	}
-
-	// read package data
-	name := p.string()
-	var path string
-	if p.version >= 5 {
-		path = p.path()
-	} else {
-		path = p.string()
-	}
-	if p.version >= 6 {
-		p.int() // package height; unused by go/types
-	}
-
-	// we should never see an empty package name
-	if name == "" {
-		errorf("empty package name in import")
-	}
-
-	// an empty path denotes the package we are currently importing;
-	// it must be the first package we see
-	if (path == "") != (len(p.pkgList) == 0) {
-		errorf("package path %q for pkg index %d", path, len(p.pkgList))
-	}
-
-	// if the package was imported before, use that one; otherwise create a new one
-	if path == "" {
-		path = p.importpath
-	}
-	pkg := p.imports[path]
-	if pkg == nil {
-		pkg = types.NewPackage(path, name)
-		p.imports[path] = pkg
-	} else if pkg.Name() != name {
-		errorf("conflicting names %s and %s for package %q", pkg.Name(), name, path)
-	}
-	p.pkgList = append(p.pkgList, pkg)
-
-	return pkg
-}
-
-// objTag returns the tag value for each object kind.
-func objTag(obj types.Object) int {
-	switch obj.(type) {
-	case *types.Const:
-		return constTag
-	case *types.TypeName:
-		return typeTag
-	case *types.Var:
-		return varTag
-	case *types.Func:
-		return funcTag
-	default:
-		errorf("unexpected object: %v (%T)", obj, obj) // panics
-		panic("unreachable")
-	}
-}
-
-func sameObj(a, b types.Object) bool {
-	// Because unnamed types are not canonicalized, we cannot simply compare types for
-	// (pointer) identity.
-	// Ideally we'd check equality of constant values as well, but this is good enough.
-	return objTag(a) == objTag(b) && types.Identical(a.Type(), b.Type())
-}
-
-func (p *importer) declare(obj types.Object) {
-	pkg := obj.Pkg()
-	if alt := pkg.Scope().Insert(obj); alt != nil {
-		// This can only trigger if we import a (non-type) object a second time.
-		// Excluding type aliases, this cannot happen because 1) we only import a package
-		// once; and b) we ignore compiler-specific export data which may contain
-		// functions whose inlined function bodies refer to other functions that
-		// were already imported.
-		// However, type aliases require reexporting the original type, so we need
-		// to allow it (see also the comment in cmd/compile/internal/gc/bimport.go,
-		// method importer.obj, switch case importing functions).
-		// TODO(gri) review/update this comment once the gc compiler handles type aliases.
-		if !sameObj(obj, alt) {
-			errorf("inconsistent import:\n\t%v\npreviously imported as:\n\t%v\n", obj, alt)
-		}
-	}
-}
-
-func (p *importer) obj(tag int) {
-	switch tag {
-	case constTag:
-		pos := p.pos()
-		pkg, name := p.qualifiedName()
-		typ := p.typ(nil, nil)
-		val := p.value()
-		p.declare(types.NewConst(pos, pkg, name, typ, val))
-
-	case aliasTag:
-		// TODO(gri) verify type alias hookup is correct
-		pos := p.pos()
-		pkg, name := p.qualifiedName()
-		typ := p.typ(nil, nil)
-		p.declare(types.NewTypeName(pos, pkg, name, typ))
-
-	case typeTag:
-		p.typ(nil, nil)
-
-	case varTag:
-		pos := p.pos()
-		pkg, name := p.qualifiedName()
-		typ := p.typ(nil, nil)
-		p.declare(types.NewVar(pos, pkg, name, typ))
-
-	case funcTag:
-		pos := p.pos()
-		pkg, name := p.qualifiedName()
-		params, isddd := p.paramList()
-		result, _ := p.paramList()
-		sig := types.NewSignature(nil, params, result, isddd)
-		p.declare(types.NewFunc(pos, pkg, name, sig))
-
-	default:
-		errorf("unexpected object tag %d", tag)
-	}
-}
-
 const deltaNewFile = -64 // see cmd/compile/internal/gc/bexport.go
 
-func (p *importer) pos() token.Pos {
-	if !p.posInfoFormat {
-		return token.NoPos
-	}
-
-	file := p.prevFile
-	line := p.prevLine
-	delta := p.int()
-	line += delta
-	if p.version >= 5 {
-		if delta == deltaNewFile {
-			if n := p.int(); n >= 0 {
-				// file changed
-				file = p.path()
-				line = n
-			}
-		}
-	} else {
-		if delta == 0 {
-			if n := p.int(); n >= 0 {
-				// file changed
-				file = p.prevFile[:n] + p.string()
-				line = p.int()
-			}
-		}
-	}
-	p.prevFile = file
-	p.prevLine = line
-
-	return p.fake.pos(file, line, 0)
-}
-
 // Synthesize a token.Pos
 type fakeFileSet struct {
 	fset  *token.FileSet
@@ -389,205 +73,6 @@ var (
 	fakeLinesOnce sync.Once
 )
 
-func (p *importer) qualifiedName() (pkg *types.Package, name string) {
-	name = p.string()
-	pkg = p.pkg()
-	return
-}
-
-func (p *importer) record(t types.Type) {
-	p.typList = append(p.typList, t)
-}
-
-// A dddSlice is a types.Type representing ...T parameters.
-// It only appears for parameter types and does not escape
-// the importer.
-type dddSlice struct {
-	elem types.Type
-}
-
-func (t *dddSlice) Underlying() types.Type { return t }
-func (t *dddSlice) String() string         { return "..." + t.elem.String() }
-
-// parent is the package which declared the type; parent == nil means
-// the package currently imported. The parent package is needed for
-// exported struct fields and interface methods which don't contain
-// explicit package information in the export data.
-//
-// A non-nil tname is used as the "owner" of the result type; i.e.,
-// the result type is the underlying type of tname. tname is used
-// to give interface methods a named receiver type where possible.
-func (p *importer) typ(parent *types.Package, tname *types.Named) types.Type {
-	// if the type was seen before, i is its index (>= 0)
-	i := p.tagOrIndex()
-	if i >= 0 {
-		return p.typList[i]
-	}
-
-	// otherwise, i is the type tag (< 0)
-	switch i {
-	case namedTag:
-		// read type object
-		pos := p.pos()
-		parent, name := p.qualifiedName()
-		scope := parent.Scope()
-		obj := scope.Lookup(name)
-
-		// if the object doesn't exist yet, create and insert it
-		if obj == nil {
-			obj = types.NewTypeName(pos, parent, name, nil)
-			scope.Insert(obj)
-		}
-
-		if _, ok := obj.(*types.TypeName); !ok {
-			errorf("pkg = %s, name = %s => %s", parent, name, obj)
-		}
-
-		// associate new named type with obj if it doesn't exist yet
-		t0 := types.NewNamed(obj.(*types.TypeName), nil, nil)
-
-		// but record the existing type, if any
-		tname := obj.Type().(*types.Named) // tname is either t0 or the existing type
-		p.record(tname)
-
-		// read underlying type
-		t0.SetUnderlying(p.typ(parent, t0))
-
-		// interfaces don't have associated methods
-		if types.IsInterface(t0) {
-			return tname
-		}
-
-		// read associated methods
-		for i := p.int(); i > 0; i-- {
-			// TODO(gri) replace this with something closer to fieldName
-			pos := p.pos()
-			name := p.string()
-			if !exported(name) {
-				p.pkg()
-			}
-
-			recv, _ := p.paramList() // TODO(gri) do we need a full param list for the receiver?
-			params, isddd := p.paramList()
-			result, _ := p.paramList()
-			p.int() // go:nointerface pragma - discarded
-
-			sig := types.NewSignature(recv.At(0), params, result, isddd)
-			t0.AddMethod(types.NewFunc(pos, parent, name, sig))
-		}
-
-		return tname
-
-	case arrayTag:
-		t := new(types.Array)
-		if p.trackAllTypes {
-			p.record(t)
-		}
-
-		n := p.int64()
-		*t = *types.NewArray(p.typ(parent, nil), n)
-		return t
-
-	case sliceTag:
-		t := new(types.Slice)
-		if p.trackAllTypes {
-			p.record(t)
-		}
-
-		*t = *types.NewSlice(p.typ(parent, nil))
-		return t
-
-	case dddTag:
-		t := new(dddSlice)
-		if p.trackAllTypes {
-			p.record(t)
-		}
-
-		t.elem = p.typ(parent, nil)
-		return t
-
-	case structTag:
-		t := new(types.Struct)
-		if p.trackAllTypes {
-			p.record(t)
-		}
-
-		*t = *types.NewStruct(p.fieldList(parent))
-		return t
-
-	case pointerTag:
-		t := new(types.Pointer)
-		if p.trackAllTypes {
-			p.record(t)
-		}
-
-		*t = *types.NewPointer(p.typ(parent, nil))
-		return t
-
-	case signatureTag:
-		t := new(types.Signature)
-		if p.trackAllTypes {
-			p.record(t)
-		}
-
-		params, isddd := p.paramList()
-		result, _ := p.paramList()
-		*t = *types.NewSignature(nil, params, result, isddd)
-		return t
-
-	case interfaceTag:
-		// Create a dummy entry in the type list. This is safe because we
-		// cannot expect the interface type to appear in a cycle, as any
-		// such cycle must contain a named type which would have been
-		// first defined earlier.
-		// TODO(gri) Is this still true now that we have type aliases?
-		// See issue #23225.
-		n := len(p.typList)
-		if p.trackAllTypes {
-			p.record(nil)
-		}
-
-		var embeddeds []types.Type
-		for n := p.int(); n > 0; n-- {
-			p.pos()
-			embeddeds = append(embeddeds, p.typ(parent, nil))
-		}
-
-		t := newInterface(p.methodList(parent, tname), embeddeds)
-		p.interfaceList = append(p.interfaceList, t)
-		if p.trackAllTypes {
-			p.typList[n] = t
-		}
-		return t
-
-	case mapTag:
-		t := new(types.Map)
-		if p.trackAllTypes {
-			p.record(t)
-		}
-
-		key := p.typ(parent, nil)
-		val := p.typ(parent, nil)
-		*t = *types.NewMap(key, val)
-		return t
-
-	case chanTag:
-		t := new(types.Chan)
-		if p.trackAllTypes {
-			p.record(t)
-		}
-
-		dir := chanDir(p.int())
-		val := p.typ(parent, nil)
-		*t = *types.NewChan(dir, val)
-		return t
-
-	default:
-		errorf("unexpected type tag %d", i) // panics
-		panic("unreachable")
-	}
-}
-
 func chanDir(d int) types.ChanDir {
 	// tag values must match the constants in cmd/compile/internal/gc/go.go
 	switch d {
@@ -603,394 +88,6 @@ func chanDir(d int) types.ChanDir {
 	}
 }
 
-func (p *importer) fieldList(parent *types.Package) (fields []*types.Var, tags []string) {
-	if n := p.int(); n > 0 {
-		fields = make([]*types.Var, n)
-		tags = make([]string, n)
-		for i := range fields {
-			fields[i], tags[i] = p.field(parent)
-		}
-	}
-	return
-}
-
-func (p *importer) field(parent *types.Package) (*types.Var, string) {
-	pos := p.pos()
-	pkg, name, alias := p.fieldName(parent)
-	typ := p.typ(parent, nil)
-	tag := p.string()
-
-	anonymous := false
-	if name == "" {
-		// anonymous field - typ must be T or *T and T must be a type name
-		switch typ := deref(typ).(type) {
-		case *types.Basic: // basic types are named types
-			pkg = nil // // objects defined in Universe scope have no package
-			name = typ.Name()
-		case *types.Named:
-			name = typ.Obj().Name()
-		default:
-			errorf("named base type expected")
-		}
-		anonymous = true
-	} else if alias {
-		// anonymous field: we have an explicit name because it's an alias
-		anonymous = true
-	}
-
-	return types.NewField(pos, pkg, name, typ, anonymous), tag
-}
-
-func (p *importer) methodList(parent *types.Package, baseType *types.Named) (methods []*types.Func) {
-	if n := p.int(); n > 0 {
-		methods = make([]*types.Func, n)
-		for i := range methods {
-			methods[i] = p.method(parent, baseType)
-		}
-	}
-	return
-}
-
-func (p *importer) method(parent *types.Package, baseType *types.Named) *types.Func {
-	pos := p.pos()
-	pkg, name, _ := p.fieldName(parent)
-	// If we don't have a baseType, use a nil receiver.
-	// A receiver using the actual interface type (which
-	// we don't know yet) will be filled in when we call
-	// types.Interface.Complete.
-	var recv *types.Var
-	if baseType != nil {
-		recv = types.NewVar(token.NoPos, parent, "", baseType)
-	}
-	params, isddd := p.paramList()
-	result, _ := p.paramList()
-	sig := types.NewSignature(recv, params, result, isddd)
-	return types.NewFunc(pos, pkg, name, sig)
-}
-
-func (p *importer) fieldName(parent *types.Package) (pkg *types.Package, name string, alias bool) {
-	name = p.string()
-	pkg = parent
-	if pkg == nil {
-		// use the imported package instead
-		pkg = p.pkgList[0]
-	}
-	if p.version == 0 && name == "_" {
-		// version 0 didn't export a package for _ fields
-		return
-	}
-	switch name {
-	case "":
-		// 1) field name matches base type name and is exported: nothing to do
-	case "?":
-		// 2) field name matches base type name and is not exported: need package
-		name = ""
-		pkg = p.pkg()
-	case "@":
-		// 3) field name doesn't match type name (alias)
-		name = p.string()
-		alias = true
-		fallthrough
-	default:
-		if !exported(name) {
-			pkg = p.pkg()
-		}
-	}
-	return
-}
-
-func (p *importer) paramList() (*types.Tuple, bool) {
-	n := p.int()
-	if n == 0 {
-		return nil, false
-	}
-	// negative length indicates unnamed parameters
-	named := true
-	if n < 0 {
-		n = -n
-		named = false
-	}
-	// n > 0
-	params := make([]*types.Var, n)
-	isddd := false
-	for i := range params {
-		params[i], isddd = p.param(named)
-	}
-	return types.NewTuple(params...), isddd
-}
-
-func (p *importer) param(named bool) (*types.Var, bool) {
-	t := p.typ(nil, nil)
-	td, isddd := t.(*dddSlice)
-	if isddd {
-		t = types.NewSlice(td.elem)
-	}
-
-	var pkg *types.Package
-	var name string
-	if named {
-		name = p.string()
-		if name == "" {
-			errorf("expected named parameter")
-		}
-		if name != "_" {
-			pkg = p.pkg()
-		}
-		if i := strings.Index(name, "·"); i > 0 {
-			name = name[:i] // cut off gc-specific parameter numbering
-		}
-	}
-
-	// read and discard compiler-specific info
-	p.string()
-
-	return types.NewVar(token.NoPos, pkg, name, t), isddd
-}
-
-func exported(name string) bool {
-	ch, _ := utf8.DecodeRuneInString(name)
-	return unicode.IsUpper(ch)
-}
-
-func (p *importer) value() constant.Value {
-	switch tag := p.tagOrIndex(); tag {
-	case falseTag:
-		return constant.MakeBool(false)
-	case trueTag:
-		return constant.MakeBool(true)
-	case int64Tag:
-		return constant.MakeInt64(p.int64())
-	case floatTag:
-		return p.float()
-	case complexTag:
-		re := p.float()
-		im := p.float()
-		return constant.BinaryOp(re, token.ADD, constant.MakeImag(im))
-	case stringTag:
-		return constant.MakeString(p.string())
-	case unknownTag:
-		return constant.MakeUnknown()
-	default:
-		errorf("unexpected value tag %d", tag) // panics
-		panic("unreachable")
-	}
-}
-
-func (p *importer) float() constant.Value {
-	sign := p.int()
-	if sign == 0 {
-		return constant.MakeInt64(0)
-	}
-
-	exp := p.int()
-	mant := []byte(p.string()) // big endian
-
-	// remove leading 0's if any
-	for len(mant) > 0 && mant[0] == 0 {
-		mant = mant[1:]
-	}
-
-	// convert to little endian
-	// TODO(gri) go/constant should have a more direct conversion function
-	//           (e.g., once it supports a big.Float based implementation)
-	for i, j := 0, len(mant)-1; i < j; i, j = i+1, j-1 {
-		mant[i], mant[j] = mant[j], mant[i]
-	}
-
-	// adjust exponent (constant.MakeFromBytes creates an integer value,
-	// but mant represents the mantissa bits such that 0.5 <= mant < 1.0)
-	exp -= len(mant) << 3
-	if len(mant) > 0 {
-		for msd := mant[len(mant)-1]; msd&0x80 == 0; msd <<= 1 {
-			exp++
-		}
-	}
-
-	x := constant.MakeFromBytes(mant)
-	switch {
-	case exp < 0:
-		d := constant.Shift(constant.MakeInt64(1), token.SHL, uint(-exp))
-		x = constant.BinaryOp(x, token.QUO, d)
-	case exp > 0:
-		x = constant.Shift(x, token.SHL, uint(exp))
-	}
-
-	if sign < 0 {
-		x = constant.UnaryOp(token.SUB, x, 0)
-	}
-	return x
-}
-
-// ----------------------------------------------------------------------------
-// Low-level decoders
-
-func (p *importer) tagOrIndex() int {
-	if p.debugFormat {
-		p.marker('t')
-	}
-
-	return int(p.rawInt64())
-}
-
-func (p *importer) int() int {
-	x := p.int64()
-	if int64(int(x)) != x {
-		errorf("exported integer too large")
-	}
-	return int(x)
-}
-
-func (p *importer) int64() int64 {
-	if p.debugFormat {
-		p.marker('i')
-	}
-
-	return p.rawInt64()
-}
-
-func (p *importer) path() string {
-	if p.debugFormat {
-		p.marker('p')
-	}
-	// if the path was seen before, i is its index (>= 0)
-	// (the empty string is at index 0)
-	i := p.rawInt64()
-	if i >= 0 {
-		return p.pathList[i]
-	}
-	// otherwise, i is the negative path length (< 0)
-	a := make([]string, -i)
-	for n := range a {
-		a[n] = p.string()
-	}
-	s := strings.Join(a, "/")
-	p.pathList = append(p.pathList, s)
-	return s
-}
-
-func (p *importer) string() string {
-	if p.debugFormat {
-		p.marker('s')
-	}
-	// if the string was seen before, i is its index (>= 0)
-	// (the empty string is at index 0)
-	i := p.rawInt64()
-	if i >= 0 {
-		return p.strList[i]
-	}
-	// otherwise, i is the negative string length (< 0)
-	if n := int(-i); n <= cap(p.buf) {
-		p.buf = p.buf[:n]
-	} else {
-		p.buf = make([]byte, n)
-	}
-	for i := range p.buf {
-		p.buf[i] = p.rawByte()
-	}
-	s := string(p.buf)
-	p.strList = append(p.strList, s)
-	return s
-}
-
-func (p *importer) marker(want byte) {
-	if got := p.rawByte(); got != want {
-		errorf("incorrect marker: got %c; want %c (pos = %d)", got, want, p.read)
-	}
-
-	pos := p.read
-	if n := int(p.rawInt64()); n != pos {
-		errorf("incorrect position: got %d; want %d", n, pos)
-	}
-}
-
-// rawInt64 should only be used by low-level decoders.
-func (p *importer) rawInt64() int64 {
-	i, err := binary.ReadVarint(p)
-	if err != nil {
-		errorf("read error: %v", err)
-	}
-	return i
-}
-
-// rawStringln should only be used to read the initial version string.
-func (p *importer) rawStringln(b byte) string {
-	p.buf = p.buf[:0]
-	for b != '\n' {
-		p.buf = append(p.buf, b)
-		b = p.rawByte()
-	}
-	return string(p.buf)
-}
-
-// needed for binary.ReadVarint in rawInt64
-func (p *importer) ReadByte() (byte, error) {
-	return p.rawByte(), nil
-}
-
-// byte is the bottleneck interface for reading p.data.
-// It unescapes '|' 'S' to '$' and '|' '|' to '|'.
-// rawByte should only be used by low-level decoders.
-func (p *importer) rawByte() byte {
-	b := p.data[0]
-	r := 1
-	if b == '|' {
-		b = p.data[1]
-		r = 2
-		switch b {
-		case 'S':
-			b = '$'
-		case '|':
-			// nothing to do
-		default:
-			errorf("unexpected escape sequence in export data")
-		}
-	}
-	p.data = p.data[r:]
-	p.read += r
-	return b
-
-}
-
-// ----------------------------------------------------------------------------
-// Export format
-
-// Tags. Must be < 0.
-const (
-	// Objects
-	packageTag = -(iota + 1)
-	constTag
-	typeTag
-	varTag
-	funcTag
-	endTag
-
-	// Types
-	namedTag
-	arrayTag
-	sliceTag
-	dddTag
-	structTag
-	pointerTag
-	signatureTag
-	interfaceTag
-	mapTag
-	chanTag
-
-	// Values
-	falseTag
-	trueTag
-	int64Tag
-	floatTag
-	fractionTag // not used by gc
-	complexTag
-	stringTag
-	nilTag     // only used by gc (appears in exported inlined function bodies)
-	unknownTag // not used by gc (only appears in packages with errors)
-
-	// Type aliases
-	aliasTag
-)
-
 var predeclOnce sync.Once
 var predecl []types.Type // initialized lazily
 

vendor/golang.org/x/tools/internal/gcimporter/gcimporter.go

@@ -7,6 +7,18 @@
 // Package gcimporter provides various functions for reading
 // gc-generated object files that can be used to implement the
 // Importer interface defined by the Go 1.5 standard library package.
+//
+// The encoding is deterministic: if the encoder is applied twice to
+// the same types.Package data structure, both encodings are equal.
+// This property may be important to avoid spurious changes in
+// applications such as build systems.
+//
+// However, the encoder is not necessarily idempotent. Importing an
+// exported package may yield a types.Package that, while it
+// represents the same set of Go types as the original, may differ in
+// the details of its internal representation. Because of these
+// differences, re-encoding the imported package may yield a
+// different, but equally valid, encoding of the package.
 package gcimporter // import "golang.org/x/tools/internal/gcimporter"
 
 import (
@@ -218,20 +230,17 @@ func Import(packages map[string]*types.Package, path, srcDir string, lookup func
 		// Or, define a new standard go/types/gcexportdata package.
 		fset := token.NewFileSet()
 
-		// The indexed export format starts with an 'i'; the older
+		// Select appropriate importer.
-		// binary export format starts with a 'c', 'd', or 'v'
-		// (from "version"). Select appropriate importer.
 		if len(data) > 0 {
 			switch data[0] {
-			case 'i':
+			case 'v', 'c', 'd': // binary, till go1.10
+				return nil, fmt.Errorf("binary (%c) import format is no longer supported", data[0])
+
+			case 'i': // indexed, till go1.19
 				_, pkg, err := IImportData(fset, packages, data[1:], id)
 				return pkg, err
 
-			case 'v', 'c', 'd':
+			case 'u': // unified, from go1.20
-				_, pkg, err := BImportData(fset, packages, data, id)
-				return pkg, err
-
-			case 'u':
 				_, pkg, err := UImportData(fset, packages, data[1:size], id)
 				return pkg, err
 

vendor/golang.org/x/tools/internal/gcimporter/iexport.go

@@ -22,17 +22,23 @@ import (
 	"strconv"
 	"strings"
 
+	"golang.org/x/tools/go/types/objectpath"
 	"golang.org/x/tools/internal/tokeninternal"
 	"golang.org/x/tools/internal/typeparams"
 )
 
 // IExportShallow encodes "shallow" export data for the specified package.
 //
-// No promises are made about the encoding other than that it can be
+// No promises are made about the encoding other than that it can be decoded by
-// decoded by the same version of IIExportShallow. If you plan to save
+// the same version of IIExportShallow. If you plan to save export data in the
-// export data in the file system, be sure to include a cryptographic
+// file system, be sure to include a cryptographic digest of the executable in
-// digest of the executable in the key to avoid version skew.
+// the key to avoid version skew.
-func IExportShallow(fset *token.FileSet, pkg *types.Package) ([]byte, error) {
+//
+// If the provided reportf func is non-nil, it will be used for reporting bugs
+// encountered during export.
+// TODO(rfindley): remove reportf when we are confident enough in the new
+// objectpath encoding.
+func IExportShallow(fset *token.FileSet, pkg *types.Package, reportf ReportFunc) ([]byte, error) {
 	// In principle this operation can only fail if out.Write fails,
 	// but that's impossible for bytes.Buffer---and as a matter of
 	// fact iexportCommon doesn't even check for I/O errors.
@@ -44,22 +50,30 @@ func IExportShallow(fset *token.FileSet, pkg *types.Package) ([]byte, error) {
 	return out.Bytes(), err
 }
 
-// IImportShallow decodes "shallow" types.Package data encoded by IExportShallow
+// IImportShallow decodes "shallow" types.Package data encoded by
-// in the same executable. This function cannot import data from
+// IExportShallow in the same executable. This function cannot import data from
 // cmd/compile or gcexportdata.Write.
-func IImportShallow(fset *token.FileSet, imports map[string]*types.Package, data []byte, path string, insert InsertType) (*types.Package, error) {
+//
+// The importer calls getPackages to obtain package symbols for all
+// packages mentioned in the export data, including the one being
+// decoded.
+//
+// If the provided reportf func is non-nil, it will be used for reporting bugs
+// encountered during import.
+// TODO(rfindley): remove reportf when we are confident enough in the new
+// objectpath encoding.
+func IImportShallow(fset *token.FileSet, getPackages GetPackagesFunc, data []byte, path string, reportf ReportFunc) (*types.Package, error) {
 	const bundle = false
-	pkgs, err := iimportCommon(fset, imports, data, bundle, path, insert)
+	const shallow = true
+	pkgs, err := iimportCommon(fset, getPackages, data, bundle, path, shallow, reportf)
 	if err != nil {
 		return nil, err
 	}
 	return pkgs[0], nil
 }
 
-// InsertType is the type of a function that creates a types.TypeName
+// ReportFunc is the type of a function used to report formatted bugs.
-// object for a named type and inserts it into the scope of the
+type ReportFunc = func(string, ...interface{})
-// specified Package.
-type InsertType = func(pkg *types.Package, name string)
 
 // Current bundled export format version. Increase with each format change.
 // 0: initial implementation
@@ -313,8 +327,9 @@ type iexporter struct {
 	out     *bytes.Buffer
 	version int
 
-	shallow  bool           // don't put types from other packages in the index
+	shallow    bool                // don't put types from other packages in the index
-	localpkg *types.Package // (nil in bundle mode)
+	objEncoder *objectpath.Encoder // encodes objects from other packages in shallow mode; lazily allocated
+	localpkg   *types.Package      // (nil in bundle mode)
 
 	// allPkgs tracks all packages that have been referenced by
 	// the export data, so we can ensure to include them in the
@@ -354,6 +369,17 @@ func (p *iexporter) trace(format string, args ...interface{}) {
 	fmt.Printf(strings.Repeat("..", p.indent)+format+"\n", args...)
 }
 
+// objectpathEncoder returns the lazily allocated objectpath.Encoder to use
+// when encoding objects in other packages during shallow export.
+//
+// Using a shared Encoder amortizes some of cost of objectpath search.
+func (p *iexporter) objectpathEncoder() *objectpath.Encoder {
+	if p.objEncoder == nil {
+		p.objEncoder = new(objectpath.Encoder)
+	}
+	return p.objEncoder
+}
+
 // stringOff returns the offset of s within the string section.
 // If not already present, it's added to the end.
 func (p *iexporter) stringOff(s string) uint64 {
@@ -413,7 +439,6 @@ type exportWriter struct {
 	p *iexporter
 
 	data       intWriter
-	currPkg    *types.Package
 	prevFile   string
 	prevLine   int64
 	prevColumn int64
@@ -436,7 +461,6 @@ func (p *iexporter) doDecl(obj types.Object) {
 		}()
 	}
 	w := p.newWriter()
-	w.setPkg(obj.Pkg(), false)
 
 	switch obj := obj.(type) {
 	case *types.Var:
@@ -673,6 +697,9 @@ func (w *exportWriter) qualifiedType(obj *types.TypeName) {
 	w.pkg(obj.Pkg())
 }
 
+// TODO(rfindley): what does 'pkg' even mean here? It would be better to pass
+// it in explicitly into signatures and structs that may use it for
+// constructing fields.
 func (w *exportWriter) typ(t types.Type, pkg *types.Package) {
 	w.data.uint64(w.p.typOff(t, pkg))
 }
@@ -764,30 +791,53 @@ func (w *exportWriter) doTyp(t types.Type, pkg *types.Package) {
 
 	case *types.Signature:
 		w.startType(signatureType)
-		w.setPkg(pkg, true)
+		w.pkg(pkg)
 		w.signature(t)
 
 	case *types.Struct:
 		w.startType(structType)
 		n := t.NumFields()
+		// Even for struct{} we must emit some qualifying package, because that's
+		// what the compiler does, and thus that's what the importer expects.
+		fieldPkg := pkg
 		if n > 0 {
-			w.setPkg(t.Field(0).Pkg(), true) // qualifying package for field objects
+			fieldPkg = t.Field(0).Pkg()
-		} else {
-			w.setPkg(pkg, true)
 		}
+		if fieldPkg == nil {
+			// TODO(rfindley): improve this very hacky logic.
+			//
+			// The importer expects a package to be set for all struct types, even
+			// those with no fields. A better encoding might be to set NumFields
+			// before pkg. setPkg panics with a nil package, which may be possible
+			// to reach with invalid packages (and perhaps valid packages, too?), so
+			// (arbitrarily) set the localpkg if available.
+			//
+			// Alternatively, we may be able to simply guarantee that pkg != nil, by
+			// reconsidering the encoding of constant values.
+			if w.p.shallow {
+				fieldPkg = w.p.localpkg
+			} else {
+				panic(internalErrorf("no package to set for empty struct"))
+			}
+		}
+		w.pkg(fieldPkg)
 		w.uint64(uint64(n))
+
 		for i := 0; i < n; i++ {
 			f := t.Field(i)
+			if w.p.shallow {
+				w.objectPath(f)
+			}
 			w.pos(f.Pos())
 			w.string(f.Name()) // unexported fields implicitly qualified by prior setPkg
-			w.typ(f.Type(), pkg)
+			w.typ(f.Type(), fieldPkg)
 			w.bool(f.Anonymous())
 			w.string(t.Tag(i)) // note (or tag)
 		}
 
 	case *types.Interface:
 		w.startType(interfaceType)
-		w.setPkg(pkg, true)
+		w.pkg(pkg)
 
 		n := t.NumEmbeddeds()
 		w.uint64(uint64(n))
@@ -802,10 +852,16 @@ func (w *exportWriter) doTyp(t types.Type, pkg *types.Package) {
 			w.typ(ft, tPkg)
 		}
 
+		// See comment for struct fields. In shallow mode we change the encoding
+		// for interface methods that are promoted from other packages.
+
 		n = t.NumExplicitMethods()
 		w.uint64(uint64(n))
 		for i := 0; i < n; i++ {
 			m := t.ExplicitMethod(i)
+			if w.p.shallow {
+				w.objectPath(m)
+			}
 			w.pos(m.Pos())
 			w.string(m.Name())
 			sig, _ := m.Type().(*types.Signature)
@@ -827,12 +883,61 @@ func (w *exportWriter) doTyp(t types.Type, pkg *types.Package) {
 	}
 }
 
-func (w *exportWriter) setPkg(pkg *types.Package, write bool) {
+// objectPath writes the package and objectPath to use to look up obj in a
-	if write {
+// different package, when encoding in "shallow" mode.
-		w.pkg(pkg)
+//
+// When doing a shallow import, the importer creates only the local package,
+// and requests package symbols for dependencies from the client.
+// However, certain types defined in the local package may hold objects defined
+// (perhaps deeply) within another package.
+//
+// For example, consider the following:
+//
+//	package a
+//	func F() chan * map[string] struct { X int }
+//
+//	package b
+//	import "a"
+//	var B = a.F()
+//
+// In this example, the type of b.B holds fields defined in package a.
+// In order to have the correct canonical objects for the field defined in the
+// type of B, they are encoded as objectPaths and later looked up in the
+// importer. The same problem applies to interface methods.
+func (w *exportWriter) objectPath(obj types.Object) {
+	if obj.Pkg() == nil || obj.Pkg() == w.p.localpkg {
+		// obj.Pkg() may be nil for the builtin error.Error.
+		// In this case, or if obj is declared in the local package, no need to
+		// encode.
+		w.string("")
+		return
 	}
-
+	objectPath, err := w.p.objectpathEncoder().For(obj)
-	w.currPkg = pkg
+	if err != nil {
+		// Fall back to the empty string, which will cause the importer to create a
+		// new object, which matches earlier behavior. Creating a new object is
+		// sufficient for many purposes (such as type checking), but causes certain
+		// references algorithms to fail (golang/go#60819). However, we didn't
+		// notice this problem during months of gopls@v0.12.0 testing.
+		//
+		// TODO(golang/go#61674): this workaround is insufficient, as in the case
+		// where the field forwarded from an instantiated type that may not appear
+		// in the export data of the original package:
+		//
+		//  // package a
+		//  type A[P any] struct{ F P }
+		//
+		//  // package b
+		//  type B a.A[int]
+		//
+		// We need to update references algorithms not to depend on this
+		// de-duplication, at which point we may want to simply remove the
+		// workaround here.
+		w.string("")
+		return
+	}
+	w.string(string(objectPath))
+	w.pkg(obj.Pkg())
 }
 
 func (w *exportWriter) signature(sig *types.Signature) {
@@ -913,6 +1018,17 @@ func (w *exportWriter) value(typ types.Type, v constant.Value) {
 		w.int64(int64(v.Kind()))
 	}
 
+	if v.Kind() == constant.Unknown {
+		// golang/go#60605: treat unknown constant values as if they have invalid type
+		//
+		// This loses some fidelity over the package type-checked from source, but that
+		// is acceptable.
+		//
+		// TODO(rfindley): we should switch on the recorded constant kind rather
+		// than the constant type
+		return
+	}
+
 	switch b := typ.Underlying().(*types.Basic); b.Info() & types.IsConstType {
 	case types.IsBoolean:
 		w.bool(constant.BoolVal(v))
@@ -969,6 +1085,16 @@ func constantToFloat(x constant.Value) *big.Float {
 	return &f
 }
 
+func valueToRat(x constant.Value) *big.Rat {
+	// Convert little-endian to big-endian.
+	// I can't believe this is necessary.
+	bytes := constant.Bytes(x)
+	for i := 0; i < len(bytes)/2; i++ {
+		bytes[i], bytes[len(bytes)-1-i] = bytes[len(bytes)-1-i], bytes[i]
+	}
+	return new(big.Rat).SetInt(new(big.Int).SetBytes(bytes))
+}
+
 // mpint exports a multi-precision integer.
 //
 // For unsigned types, small values are written out as a single
@@ -1178,3 +1304,19 @@ func (q *objQueue) popHead() types.Object {
 	q.head++
 	return obj
 }
+
+// internalError represents an error generated inside this package.
+type internalError string
+
+func (e internalError) Error() string { return "gcimporter: " + string(e) }
+
+// TODO(adonovan): make this call panic, so that it's symmetric with errorf.
+// Otherwise it's easy to forget to do anything with the error.
+//
+// TODO(adonovan): also, consider switching the names "errorf" and
+// "internalErrorf" as the former is used for bugs, whose cause is
+// internal inconsistency, whereas the latter is used for ordinary
+// situations like bad input, whose cause is external.
+func internalErrorf(format string, args ...interface{}) error {
+	return internalError(fmt.Sprintf(format, args...))
+}

vendor/golang.org/x/tools/internal/gcimporter/iimport.go

@@ -21,6 +21,7 @@ import (
 	"sort"
 	"strings"
 
+	"golang.org/x/tools/go/types/objectpath"
 	"golang.org/x/tools/internal/typeparams"
 )
 
@@ -85,7 +86,7 @@ const (
 // If the export data version is not recognized or the format is otherwise
 // compromised, an error is returned.
 func IImportData(fset *token.FileSet, imports map[string]*types.Package, data []byte, path string) (int, *types.Package, error) {
-	pkgs, err := iimportCommon(fset, imports, data, false, path, nil)
+	pkgs, err := iimportCommon(fset, GetPackagesFromMap(imports), data, false, path, false, nil)
 	if err != nil {
 		return 0, nil, err
 	}
@@ -94,10 +95,49 @@ func IImportData(fset *token.FileSet, imports map[string]*types.Package, data []
 
 // IImportBundle imports a set of packages from the serialized package bundle.
 func IImportBundle(fset *token.FileSet, imports map[string]*types.Package, data []byte) ([]*types.Package, error) {
-	return iimportCommon(fset, imports, data, true, "", nil)
+	return iimportCommon(fset, GetPackagesFromMap(imports), data, true, "", false, nil)
 }
 
-func iimportCommon(fset *token.FileSet, imports map[string]*types.Package, data []byte, bundle bool, path string, insert InsertType) (pkgs []*types.Package, err error) {
+// A GetPackagesFunc function obtains the non-nil symbols for a set of
+// packages, creating and recursively importing them as needed. An
+// implementation should store each package symbol is in the Pkg
+// field of the items array.
+//
+// Any error causes importing to fail. This can be used to quickly read
+// the import manifest of an export data file without fully decoding it.
+type GetPackagesFunc = func(items []GetPackagesItem) error
+
+// A GetPackagesItem is a request from the importer for the package
+// symbol of the specified name and path.
+type GetPackagesItem struct {
+	Name, Path string
+	Pkg        *types.Package // to be filled in by GetPackagesFunc call
+
+	// private importer state
+	pathOffset uint64
+	nameIndex  map[string]uint64
+}
+
+// GetPackagesFromMap returns a GetPackagesFunc that retrieves
+// packages from the given map of package path to package.
+//
+// The returned function may mutate m: each requested package that is not
+// found is created with types.NewPackage and inserted into m.
+func GetPackagesFromMap(m map[string]*types.Package) GetPackagesFunc {
+	return func(items []GetPackagesItem) error {
+		for i, item := range items {
+			pkg, ok := m[item.Path]
+			if !ok {
+				pkg = types.NewPackage(item.Path, item.Name)
+				m[item.Path] = pkg
+			}
+			items[i].Pkg = pkg
+		}
+		return nil
+	}
+}
+
+func iimportCommon(fset *token.FileSet, getPackages GetPackagesFunc, data []byte, bundle bool, path string, shallow bool, reportf ReportFunc) (pkgs []*types.Package, err error) {
 	const currentVersion = iexportVersionCurrent
 	version := int64(-1)
 	if !debug {
@@ -108,7 +148,7 @@ func iimportCommon(fset *token.FileSet, imports map[string]*types.Package, data
 				} else if version > currentVersion {
 					err = fmt.Errorf("cannot import %q (%v), export data is newer version - update tool", path, e)
 				} else {
-					err = fmt.Errorf("cannot import %q (%v), possibly version skew - reinstall package", path, e)
+					err = fmt.Errorf("internal error while importing %q (%v); please report an issue", path, e)
 				}
 			}
 		}()
@@ -117,11 +157,8 @@ func iimportCommon(fset *token.FileSet, imports map[string]*types.Package, data
 	r := &intReader{bytes.NewReader(data), path}
 
 	if bundle {
-		bundleVersion := r.uint64()
+		if v := r.uint64(); v != bundleVersion {
-		switch bundleVersion {
+			errorf("unknown bundle format version %d", v)
-		case bundleVersion:
-		default:
-			errorf("unknown bundle format version %d", bundleVersion)
 		}
 	}
 
@@ -139,7 +176,7 @@ func iimportCommon(fset *token.FileSet, imports map[string]*types.Package, data
 	sLen := int64(r.uint64())
 	var fLen int64
 	var fileOffset []uint64
-	if insert != nil {
+	if shallow {
 		// Shallow mode uses a different position encoding.
 		fLen = int64(r.uint64())
 		fileOffset = make([]uint64, r.uint64())
@@ -158,7 +195,8 @@ func iimportCommon(fset *token.FileSet, imports map[string]*types.Package, data
 	p := iimporter{
 		version: int(version),
 		ipath:   path,
-		insert:  insert,
+		shallow: shallow,
+		reportf: reportf,
 
 		stringData:  stringData,
 		stringCache: make(map[uint64]string),
@@ -185,8 +223,9 @@ func iimportCommon(fset *token.FileSet, imports map[string]*types.Package, data
 		p.typCache[uint64(i)] = pt
 	}
 
-	pkgList := make([]*types.Package, r.uint64())
+	// Gather the relevant packages from the manifest.
-	for i := range pkgList {
+	items := make([]GetPackagesItem, r.uint64())
+	for i := range items {
 		pkgPathOff := r.uint64()
 		pkgPath := p.stringAt(pkgPathOff)
 		pkgName := p.stringAt(r.uint64())
@@ -195,30 +234,42 @@ func iimportCommon(fset *token.FileSet, imports map[string]*types.Package, data
 		if pkgPath == "" {
 			pkgPath = path
 		}
-		pkg := imports[pkgPath]
+		items[i].Name = pkgName
-		if pkg == nil {
+		items[i].Path = pkgPath
-			pkg = types.NewPackage(pkgPath, pkgName)
+		items[i].pathOffset = pkgPathOff
-			imports[pkgPath] = pkg
-		} else if pkg.Name() != pkgName {
-			errorf("conflicting names %s and %s for package %q", pkg.Name(), pkgName, path)
-		}
-		if i == 0 && !bundle {
-			p.localpkg = pkg
-		}
-
-		p.pkgCache[pkgPathOff] = pkg
 
 		// Read index for package.
 		nameIndex := make(map[string]uint64)
 		nSyms := r.uint64()
-		// In shallow mode we don't expect an index for other packages.
+		// In shallow mode, only the current package (i=0) has an index.
-		assert(nSyms == 0 || p.localpkg == pkg || p.insert == nil)
+		assert(!(shallow && i > 0 && nSyms != 0))
 		for ; nSyms > 0; nSyms-- {
 			name := p.stringAt(r.uint64())
 			nameIndex[name] = r.uint64()
 		}
 
-		p.pkgIndex[pkg] = nameIndex
+		items[i].nameIndex = nameIndex
+	}
+
+	// Request packages all at once from the client,
+	// enabling a parallel implementation.
+	if err := getPackages(items); err != nil {
+		return nil, err // don't wrap this error
+	}
+
+	// Check the results and complete the index.
+	pkgList := make([]*types.Package, len(items))
+	for i, item := range items {
+		pkg := item.Pkg
+		if pkg == nil {
+			errorf("internal error: getPackages returned nil package for %q", item.Path)
+		} else if pkg.Path() != item.Path {
+			errorf("internal error: getPackages returned wrong path %q, want %q", pkg.Path(), item.Path)
+		} else if pkg.Name() != item.Name {
+			errorf("internal error: getPackages returned wrong name %s for package %q, want %s", pkg.Name(), item.Path, item.Name)
+		}
+		p.pkgCache[item.pathOffset] = pkg
+		p.pkgIndex[pkg] = item.nameIndex
 		pkgList[i] = pkg
 	}
 
@@ -277,6 +328,13 @@ func iimportCommon(fset *token.FileSet, imports map[string]*types.Package, data
 		typ.Complete()
 	}
 
+	// Workaround for golang/go#61561. See the doc for instanceList for details.
+	for _, typ := range p.instanceList {
+		if iface, _ := typ.Underlying().(*types.Interface); iface != nil {
+			iface.Complete()
+		}
+	}
+
 	return pkgs, nil
 }
 
@@ -289,8 +347,8 @@ type iimporter struct {
 	version int
 	ipath   string
 
-	localpkg *types.Package
+	shallow bool
-	insert   func(pkg *types.Package, name string) // "shallow" mode only
+	reportf ReportFunc // if non-nil, used to report bugs
 
 	stringData  []byte
 	stringCache map[uint64]string
@@ -307,6 +365,12 @@ type iimporter struct {
 	fake          fakeFileSet
 	interfaceList []*types.Interface
 
+	// Workaround for the go/types bug golang/go#61561: instances produced during
+	// instantiation may contain incomplete interfaces. Here we only complete the
+	// underlying type of the instance, which is the most common case but doesn't
+	// handle parameterized interface literals defined deeper in the type.
+	instanceList []types.Type // instances for later completion (see golang/go#61561)
+
 	// Arguments for calls to SetConstraint that are deferred due to recursive types
 	later []setConstraintArgs
 
@@ -338,13 +402,9 @@ func (p *iimporter) doDecl(pkg *types.Package, name string) {
 
 	off, ok := p.pkgIndex[pkg][name]
 	if !ok {
-		// In "shallow" mode, call back to the application to
+		// In deep mode, the index should be complete. In shallow
-		// find the object and insert it into the package scope.
+		// mode, we should have already recursively loaded necessary
-		if p.insert != nil {
+		// dependencies so the above Lookup succeeds.
-			assert(pkg != p.localpkg)
-			p.insert(pkg, name) // "can't fail"
-			return
-		}
 		errorf("%v.%v not in index", pkg, name)
 	}
 
@@ -711,7 +771,8 @@ func (r *importReader) qualifiedIdent() (*types.Package, string) {
 }
 
 func (r *importReader) pos() token.Pos {
-	if r.p.insert != nil { // shallow mode
+	if r.p.shallow {
+		// precise offsets are encoded only in shallow mode
 		return r.posv2()
 	}
 	if r.p.version >= iexportVersionPosCol {
@@ -812,13 +873,28 @@ func (r *importReader) doType(base *types.Named) (res types.Type) {
 		fields := make([]*types.Var, r.uint64())
 		tags := make([]string, len(fields))
 		for i := range fields {
+			var field *types.Var
+			if r.p.shallow {
+				field, _ = r.objectPathObject().(*types.Var)
+			}
+
 			fpos := r.pos()
 			fname := r.ident()
 			ftyp := r.typ()
 			emb := r.bool()
 			tag := r.string()
 
-			fields[i] = types.NewField(fpos, r.currPkg, fname, ftyp, emb)
+			// Either this is not a shallow import, the field is local, or the
+			// encoded objectPath failed to produce an object (a bug).
+			//
+			// Even in this last, buggy case, fall back on creating a new field. As
+			// discussed in iexport.go, this is not correct, but mostly works and is
+			// preferable to failing (for now at least).
+			if field == nil {
+				field = types.NewField(fpos, r.currPkg, fname, ftyp, emb)
+			}
+
+			fields[i] = field
 			tags[i] = tag
 		}
 		return types.NewStruct(fields, tags)
@@ -834,6 +910,11 @@ func (r *importReader) doType(base *types.Named) (res types.Type) {
 
 		methods := make([]*types.Func, r.uint64())
 		for i := range methods {
+			var method *types.Func
+			if r.p.shallow {
+				method, _ = r.objectPathObject().(*types.Func)
+			}
+
 			mpos := r.pos()
 			mname := r.ident()
 
@@ -843,9 +924,12 @@ func (r *importReader) doType(base *types.Named) (res types.Type) {
 			if base != nil {
 				recv = types.NewVar(token.NoPos, r.currPkg, "", base)
 			}
-
 			msig := r.signature(recv, nil, nil)
-			methods[i] = types.NewFunc(mpos, r.currPkg, mname, msig)
+
+			if method == nil {
+				method = types.NewFunc(mpos, r.currPkg, mname, msig)
+			}
+			methods[i] = method
 		}
 
 		typ := newInterface(methods, embeddeds)
@@ -883,6 +967,9 @@ func (r *importReader) doType(base *types.Named) (res types.Type) {
 		// we must always use the methods of the base (orig) type.
 		// TODO provide a non-nil *Environment
 		t, _ := typeparams.Instantiate(nil, baseType, targs, false)
+
+		// Workaround for golang/go#61561. See the doc for instanceList for details.
+		r.p.instanceList = append(r.p.instanceList, t)
 		return t
 
 	case unionType:
@@ -901,6 +988,26 @@ func (r *importReader) kind() itag {
 	return itag(r.uint64())
 }
 
+// objectPathObject is the inverse of exportWriter.objectPath.
+//
+// In shallow mode, certain fields and methods may need to be looked up in an
+// imported package. See the doc for exportWriter.objectPath for a full
+// explanation.
+func (r *importReader) objectPathObject() types.Object {
+	objPath := objectpath.Path(r.string())
+	if objPath == "" {
+		return nil
+	}
+	pkg := r.pkg()
+	obj, err := objectpath.Object(pkg, objPath)
+	if err != nil {
+		if r.p.reportf != nil {
+			r.p.reportf("failed to find object for objectPath %q: %v", objPath, err)
+		}
+	}
+	return obj
+}
+
 func (r *importReader) signature(recv *types.Var, rparams []*typeparams.TypeParam, tparams []*typeparams.TypeParam) *types.Signature {
 	params := r.paramList()
 	results := r.paramList()

vendor/golang.org/x/tools/internal/gcimporter/ureader_yes.go

@@ -10,8 +10,10 @@
 package gcimporter
 
 import (
+	"fmt"
 	"go/token"
 	"go/types"
+	"sort"
 	"strings"
 
 	"golang.org/x/tools/internal/pkgbits"
@@ -62,6 +64,14 @@ type typeInfo struct {
 }
 
 func UImportData(fset *token.FileSet, imports map[string]*types.Package, data []byte, path string) (_ int, pkg *types.Package, err error) {
+	if !debug {
+		defer func() {
+			if x := recover(); x != nil {
+				err = fmt.Errorf("internal error in importing %q (%v); please report an issue", path, x)
+			}
+		}()
+	}
+
 	s := string(data)
 	s = s[:strings.LastIndex(s, "\n$$\n")]
 	input := pkgbits.NewPkgDecoder(path, s)
@@ -121,6 +131,16 @@ func readUnifiedPackage(fset *token.FileSet, ctxt *types.Context, imports map[st
 		iface.Complete()
 	}
 
+	// Imports() of pkg are all of the transitive packages that were loaded.
+	var imps []*types.Package
+	for _, imp := range pr.pkgs {
+		if imp != nil && imp != pkg {
+			imps = append(imps, imp)
+		}
+	}
+	sort.Sort(byPath(imps))
+	pkg.SetImports(imps)
+
 	pkg.MarkComplete()
 	return pkg
 }
@@ -260,39 +280,9 @@ func (r *reader) doPkg() *types.Package {
 	pkg := types.NewPackage(path, name)
 	r.p.imports[path] = pkg
 
-	imports := make([]*types.Package, r.Len())
-	for i := range imports {
-		imports[i] = r.pkg()
-	}
-	pkg.SetImports(flattenImports(imports))
-
 	return pkg
 }
 
-// flattenImports returns the transitive closure of all imported
-// packages rooted from pkgs.
-func flattenImports(pkgs []*types.Package) []*types.Package {
-	var res []*types.Package
-	seen := make(map[*types.Package]struct{})
-	for _, pkg := range pkgs {
-		if _, ok := seen[pkg]; ok {
-			continue
-		}
-		seen[pkg] = struct{}{}
-		res = append(res, pkg)
-
-		// pkg.Imports() is already flattened.
-		for _, pkg := range pkg.Imports() {
-			if _, ok := seen[pkg]; ok {
-				continue
-			}
-			seen[pkg] = struct{}{}
-			res = append(res, pkg)
-		}
-	}
-	return res
-}
-
 // @@@ Types
 
 func (r *reader) typ() types.Type {

vendor/golang.org/x/tools/internal/gocommand/invoke.go

@@ -8,10 +8,12 @@ package gocommand
 import (
 	"bytes"
 	"context"
+	"errors"
 	"fmt"
 	"io"
 	"log"
 	"os"
+	"reflect"
 	"regexp"
 	"runtime"
 	"strconv"
@@ -22,6 +24,9 @@ import (
 	exec "golang.org/x/sys/execabs"
 
 	"golang.org/x/tools/internal/event"
+	"golang.org/x/tools/internal/event/keys"
+	"golang.org/x/tools/internal/event/label"
+	"golang.org/x/tools/internal/event/tag"
 )
 
 // An Runner will run go command invocations and serialize
@@ -51,9 +56,19 @@ func (runner *Runner) initialize() {
 // 1.14: go: updating go.mod: existing contents have changed since last read
 var modConcurrencyError = regexp.MustCompile(`go:.*go.mod.*contents have changed`)
 
+// verb is an event label for the go command verb.
+var verb = keys.NewString("verb", "go command verb")
+
+func invLabels(inv Invocation) []label.Label {
+	return []label.Label{verb.Of(inv.Verb), tag.Directory.Of(inv.WorkingDir)}
+}
+
 // Run is a convenience wrapper around RunRaw.
 // It returns only stdout and a "friendly" error.
 func (runner *Runner) Run(ctx context.Context, inv Invocation) (*bytes.Buffer, error) {
+	ctx, done := event.Start(ctx, "gocommand.Runner.Run", invLabels(inv)...)
+	defer done()
+
 	stdout, _, friendly, _ := runner.RunRaw(ctx, inv)
 	return stdout, friendly
 }
@@ -61,6 +76,9 @@ func (runner *Runner) Run(ctx context.Context, inv Invocation) (*bytes.Buffer, e
 // RunPiped runs the invocation serially, always waiting for any concurrent
 // invocations to complete first.
 func (runner *Runner) RunPiped(ctx context.Context, inv Invocation, stdout, stderr io.Writer) error {
+	ctx, done := event.Start(ctx, "gocommand.Runner.RunPiped", invLabels(inv)...)
+	defer done()
+
 	_, err := runner.runPiped(ctx, inv, stdout, stderr)
 	return err
 }
@@ -68,6 +86,8 @@ func (runner *Runner) RunPiped(ctx context.Context, inv Invocation, stdout, stde
 // RunRaw runs the invocation, serializing requests only if they fight over
 // go.mod changes.
 func (runner *Runner) RunRaw(ctx context.Context, inv Invocation) (*bytes.Buffer, *bytes.Buffer, error, error) {
+	ctx, done := event.Start(ctx, "gocommand.Runner.RunRaw", invLabels(inv)...)
+	defer done()
 	// Make sure the runner is always initialized.
 	runner.initialize()
 
@@ -215,6 +235,18 @@ func (i *Invocation) run(ctx context.Context, stdout, stderr io.Writer) error {
 	cmd := exec.Command("go", goArgs...)
 	cmd.Stdout = stdout
 	cmd.Stderr = stderr
+
+	// cmd.WaitDelay was added only in go1.20 (see #50436).
+	if waitDelay := reflect.ValueOf(cmd).Elem().FieldByName("WaitDelay"); waitDelay.IsValid() {
+		// https://go.dev/issue/59541: don't wait forever copying stderr
+		// after the command has exited.
+		// After CL 484741 we copy stdout manually, so we we'll stop reading that as
+		// soon as ctx is done. However, we also don't want to wait around forever
+		// for stderr. Give a much-longer-than-reasonable delay and then assume that
+		// something has wedged in the kernel or runtime.
+		waitDelay.Set(reflect.ValueOf(30 * time.Second))
+	}
+
 	// On darwin the cwd gets resolved to the real path, which breaks anything that
 	// expects the working directory to keep the original path, including the
 	// go command when dealing with modules.
@@ -229,6 +261,7 @@ func (i *Invocation) run(ctx context.Context, stdout, stderr io.Writer) error {
 		cmd.Env = append(cmd.Env, "PWD="+i.WorkingDir)
 		cmd.Dir = i.WorkingDir
 	}
+
 	defer func(start time.Time) { log("%s for %v", time.Since(start), cmdDebugStr(cmd)) }(time.Now())
 
 	return runCmdContext(ctx, cmd)
@@ -242,10 +275,85 @@ var DebugHangingGoCommands = false
 
 // runCmdContext is like exec.CommandContext except it sends os.Interrupt
 // before os.Kill.
-func runCmdContext(ctx context.Context, cmd *exec.Cmd) error {
+func runCmdContext(ctx context.Context, cmd *exec.Cmd) (err error) {
-	if err := cmd.Start(); err != nil {
+	// If cmd.Stdout is not an *os.File, the exec package will create a pipe and
+	// copy it to the Writer in a goroutine until the process has finished and
+	// either the pipe reaches EOF or command's WaitDelay expires.
+	//
+	// However, the output from 'go list' can be quite large, and we don't want to
+	// keep reading (and allocating buffers) if we've already decided we don't
+	// care about the output. We don't want to wait for the process to finish, and
+	// we don't wait to wait for the WaitDelay to expire either.
+	//
+	// Instead, if cmd.Stdout requires a copying goroutine we explicitly replace
+	// it with a pipe (which is an *os.File), which we can close in order to stop
+	// copying output as soon as we realize we don't care about it.
+	var stdoutW *os.File
+	if cmd.Stdout != nil {
+		if _, ok := cmd.Stdout.(*os.File); !ok {
+			var stdoutR *os.File
+			stdoutR, stdoutW, err = os.Pipe()
+			if err != nil {
+				return err
+			}
+			prevStdout := cmd.Stdout
+			cmd.Stdout = stdoutW
+
+			stdoutErr := make(chan error, 1)
+			go func() {
+				_, err := io.Copy(prevStdout, stdoutR)
+				if err != nil {
+					err = fmt.Errorf("copying stdout: %w", err)
+				}
+				stdoutErr <- err
+			}()
+			defer func() {
+				// We started a goroutine to copy a stdout pipe.
+				// Wait for it to finish, or terminate it if need be.
+				var err2 error
+				select {
+				case err2 = <-stdoutErr:
+					stdoutR.Close()
+				case <-ctx.Done():
+					stdoutR.Close()
+					// Per https://pkg.go.dev/os#File.Close, the call to stdoutR.Close
+					// should cause the Read call in io.Copy to unblock and return
+					// immediately, but we still need to receive from stdoutErr to confirm
+					// that it has happened.
+					<-stdoutErr
+					err2 = ctx.Err()
+				}
+				if err == nil {
+					err = err2
+				}
+			}()
+
+			// Per https://pkg.go.dev/os/exec#Cmd, “If Stdout and Stderr are the
+			// same writer, and have a type that can be compared with ==, at most
+			// one goroutine at a time will call Write.”
+			//
+			// Since we're starting a goroutine that writes to cmd.Stdout, we must
+			// also update cmd.Stderr so that it still holds.
+			func() {
+				defer func() { recover() }()
+				if cmd.Stderr == prevStdout {
+					cmd.Stderr = cmd.Stdout
+				}
+			}()
+		}
+	}
+
+	err = cmd.Start()
+	if stdoutW != nil {
+		// The child process has inherited the pipe file,
+		// so close the copy held in this process.
+		stdoutW.Close()
+		stdoutW = nil
+	}
+	if err != nil {
 		return err
 	}
+
 	resChan := make(chan error, 1)
 	go func() {
 		resChan <- cmd.Wait()
@@ -253,11 +361,14 @@ func runCmdContext(ctx context.Context, cmd *exec.Cmd) error {
 
 	// If we're interested in debugging hanging Go commands, stop waiting after a
 	// minute and panic with interesting information.
-	if DebugHangingGoCommands {
+	debug := DebugHangingGoCommands
+	if debug {
+		timer := time.NewTimer(1 * time.Minute)
+		defer timer.Stop()
 		select {
 		case err := <-resChan:
 			return err
-		case <-time.After(1 * time.Minute):
+		case <-timer.C:
 			HandleHangingGoCommand(cmd.Process)
 		case <-ctx.Done():
 		}
@@ -270,30 +381,25 @@ func runCmdContext(ctx context.Context, cmd *exec.Cmd) error {
 	}
 
 	// Cancelled. Interrupt and see if it ends voluntarily.
-	cmd.Process.Signal(os.Interrupt)
+	if err := cmd.Process.Signal(os.Interrupt); err == nil {
-	select {
+		// (We used to wait only 1s but this proved
-	case err := <-resChan:
+		// fragile on loaded builder machines.)
-		return err
+		timer := time.NewTimer(5 * time.Second)
-	case <-time.After(time.Second):
+		defer timer.Stop()
+		select {
+		case err := <-resChan:
+			return err
+		case <-timer.C:
+		}
 	}
 
 	// Didn't shut down in response to interrupt. Kill it hard.
 	// TODO(rfindley): per advice from bcmills@, it may be better to send SIGQUIT
 	// on certain platforms, such as unix.
-	if err := cmd.Process.Kill(); err != nil && DebugHangingGoCommands {
+	if err := cmd.Process.Kill(); err != nil && !errors.Is(err, os.ErrProcessDone) && debug {
-		// Don't panic here as this reliably fails on windows with EINVAL.
 		log.Printf("error killing the Go command: %v", err)
 	}
 
-	// See above: don't wait indefinitely if we're debugging hanging Go commands.
-	if DebugHangingGoCommands {
-		select {
-		case err := <-resChan:
-			return err
-		case <-time.After(10 * time.Second): // a shorter wait as resChan should return quickly following Kill
-			HandleHangingGoCommand(cmd.Process)
-		}
-	}
 	return <-resChan
 }
 

vendor/golang.org/x/tools/internal/gocommand/version.go

@@ -23,21 +23,11 @@ import (
 func GoVersion(ctx context.Context, inv Invocation, r *Runner) (int, error) {
 	inv.Verb = "list"
 	inv.Args = []string{"-e", "-f", `{{context.ReleaseTags}}`, `--`, `unsafe`}
-	inv.Env = append(append([]string{}, inv.Env...), "GO111MODULE=off")
+	inv.BuildFlags = nil // This is not a build command.
-	// Unset any unneeded flags, and remove them from BuildFlags, if they're
-	// present.
-	inv.ModFile = ""
 	inv.ModFlag = ""
-	var buildFlags []string
+	inv.ModFile = ""
-	for _, flag := range inv.BuildFlags {
+	inv.Env = append(inv.Env[:len(inv.Env):len(inv.Env)], "GO111MODULE=off")
-		// Flags can be prefixed by one or two dashes.
+
-		f := strings.TrimPrefix(strings.TrimPrefix(flag, "-"), "-")
-		if strings.HasPrefix(f, "mod=") || strings.HasPrefix(f, "modfile=") {
-			continue
-		}
-		buildFlags = append(buildFlags, flag)
-	}
-	inv.BuildFlags = buildFlags
 	stdoutBytes, err := r.Run(ctx, inv)
 	if err != nil {
 		return 0, err

vendor/golang.org/x/tools/internal/tokeninternal/tokeninternal.go

@@ -7,7 +7,9 @@
 package tokeninternal
 
 import (
+	"fmt"
 	"go/token"
+	"sort"
 	"sync"
 	"unsafe"
 )
@@ -57,3 +59,93 @@ func GetLines(file *token.File) []int {
 		panic("unexpected token.File size")
 	}
 }
+
+// AddExistingFiles adds the specified files to the FileSet if they
+// are not already present. It panics if any pair of files in the
+// resulting FileSet would overlap.
+func AddExistingFiles(fset *token.FileSet, files []*token.File) {
+	// Punch through the FileSet encapsulation.
+	type tokenFileSet struct {
+		// This type remained essentially consistent from go1.16 to go1.21.
+		mutex sync.RWMutex
+		base  int
+		files []*token.File
+		_     *token.File // changed to atomic.Pointer[token.File] in go1.19
+	}
+
+	// If the size of token.FileSet changes, this will fail to compile.
+	const delta = int64(unsafe.Sizeof(tokenFileSet{})) - int64(unsafe.Sizeof(token.FileSet{}))
+	var _ [-delta * delta]int
+
+	type uP = unsafe.Pointer
+	var ptr *tokenFileSet
+	*(*uP)(uP(&ptr)) = uP(fset)
+	ptr.mutex.Lock()
+	defer ptr.mutex.Unlock()
+
+	// Merge and sort.
+	newFiles := append(ptr.files, files...)
+	sort.Slice(newFiles, func(i, j int) bool {
+		return newFiles[i].Base() < newFiles[j].Base()
+	})
+
+	// Reject overlapping files.
+	// Discard adjacent identical files.
+	out := newFiles[:0]
+	for i, file := range newFiles {
+		if i > 0 {
+			prev := newFiles[i-1]
+			if file == prev {
+				continue
+			}
+			if prev.Base()+prev.Size()+1 > file.Base() {
+				panic(fmt.Sprintf("file %s (%d-%d) overlaps with file %s (%d-%d)",
+					prev.Name(), prev.Base(), prev.Base()+prev.Size(),
+					file.Name(), file.Base(), file.Base()+file.Size()))
+			}
+		}
+		out = append(out, file)
+	}
+	newFiles = out
+
+	ptr.files = newFiles
+
+	// Advance FileSet.Base().
+	if len(newFiles) > 0 {
+		last := newFiles[len(newFiles)-1]
+		newBase := last.Base() + last.Size() + 1
+		if ptr.base < newBase {
+			ptr.base = newBase
+		}
+	}
+}
+
+// FileSetFor returns a new FileSet containing a sequence of new Files with
+// the same base, size, and line as the input files, for use in APIs that
+// require a FileSet.
+//
+// Precondition: the input files must be non-overlapping, and sorted in order
+// of their Base.
+func FileSetFor(files ...*token.File) *token.FileSet {
+	fset := token.NewFileSet()
+	for _, f := range files {
+		f2 := fset.AddFile(f.Name(), f.Base(), f.Size())
+		lines := GetLines(f)
+		f2.SetLines(lines)
+	}
+	return fset
+}
+
+// CloneFileSet creates a new FileSet holding all files in fset. It does not
+// create copies of the token.Files in fset: they are added to the resulting
+// FileSet unmodified.
+func CloneFileSet(fset *token.FileSet) *token.FileSet {
+	var files []*token.File
+	fset.Iterate(func(f *token.File) bool {
+		files = append(files, f)
+		return true
+	})
+	newFileSet := token.NewFileSet()
+	AddExistingFiles(newFileSet, files)
+	return newFileSet
+}

vendor/golang.org/x/tools/internal/typeparams/common.go

@@ -23,6 +23,7 @@
 package typeparams
 
 import (
+	"fmt"
 	"go/ast"
 	"go/token"
 	"go/types"
@@ -87,7 +88,6 @@ func IsTypeParam(t types.Type) bool {
 func OriginMethod(fn *types.Func) *types.Func {
 	recv := fn.Type().(*types.Signature).Recv()
 	if recv == nil {
-
 		return fn
 	}
 	base := recv.Type()
@@ -106,6 +106,31 @@ func OriginMethod(fn *types.Func) *types.Func {
 	}
 	orig := NamedTypeOrigin(named)
 	gfn, _, _ := types.LookupFieldOrMethod(orig, true, fn.Pkg(), fn.Name())
+
+	// This is a fix for a gopls crash (#60628) due to a go/types bug (#60634). In:
+	// 	package p
+	//      type T *int
+	//      func (*T) f() {}
+	// LookupFieldOrMethod(T, true, p, f)=nil, but NewMethodSet(*T)={(*T).f}.
+	// Here we make them consistent by force.
+	// (The go/types bug is general, but this workaround is reached only
+	// for generic T thanks to the early return above.)
+	if gfn == nil {
+		mset := types.NewMethodSet(types.NewPointer(orig))
+		for i := 0; i < mset.Len(); i++ {
+			m := mset.At(i)
+			if m.Obj().Id() == fn.Id() {
+				gfn = m.Obj()
+				break
+			}
+		}
+	}
+
+	// In golang/go#61196, we observe another crash, this time inexplicable.
+	if gfn == nil {
+		panic(fmt.Sprintf("missing origin method for %s.%s; named == origin: %t, named.NumMethods(): %d, origin.NumMethods(): %d", named, fn, named == orig, named.NumMethods(), orig.NumMethods()))
+	}
+
 	return gfn.(*types.Func)
 }
 

vendor/golang.org/x/tools/internal/typeparams/coretype.go

@@ -81,13 +81,13 @@ func CoreType(T types.Type) types.Type {
 // restrictions may be arbitrarily complex. For example, consider the
 // following:
 //
-//  type A interface{ ~string|~[]byte }
+//	type A interface{ ~string|~[]byte }
 //
-//  type B interface{ int|string }
+//	type B interface{ int|string }
 //
-//  type C interface { ~string|~int }
+//	type C interface { ~string|~int }
 //
-//  type T[P interface{ A|B; C }] int
+//	type T[P interface{ A|B; C }] int
 //
 // In this example, the structural type restriction of P is ~string|int: A|B
 // expands to ~string|~[]byte|int|string, which reduces to ~string|~[]byte|int,

vendor/golang.org/x/tools/internal/typeparams/termlist.go

@@ -30,7 +30,7 @@ func (xl termlist) String() string {
 	var buf bytes.Buffer
 	for i, x := range xl {
 		if i > 0 {
-			buf.WriteString(" ∪ ")
+			buf.WriteString(" | ")
 		}
 		buf.WriteString(x.String())
 	}

vendor/golang.org/x/tools/internal/typeparams/typeparams_go117.go

@@ -129,7 +129,7 @@ func NamedTypeArgs(*types.Named) *TypeList {
 }
 
 // NamedTypeOrigin is the identity method at this Go version.
-func NamedTypeOrigin(named *types.Named) types.Type {
+func NamedTypeOrigin(named *types.Named) *types.Named {
 	return named
 }
 

vendor/golang.org/x/tools/internal/typeparams/typeparams_go118.go

@@ -103,7 +103,7 @@ func NamedTypeArgs(named *types.Named) *TypeList {
 }
 
 // NamedTypeOrigin returns named.Orig().
-func NamedTypeOrigin(named *types.Named) types.Type {
+func NamedTypeOrigin(named *types.Named) *types.Named {
 	return named.Origin()
 }
 

vendor/golang.org/x/tools/internal/typeparams/typeterm.go

@@ -10,11 +10,10 @@ import "go/types"
 
 // A term describes elementary type sets:
 //
-//   ∅:  (*term)(nil)     == ∅                      // set of no types (empty set)
+//	 ∅:  (*term)(nil)     == ∅                      // set of no types (empty set)
-//   𝓤:  &term{}          == 𝓤                      // set of all types (𝓤niverse)
+//	 𝓤:  &term{}          == 𝓤                      // set of all types (𝓤niverse)
-//   T:  &term{false, T}  == {T}                    // set of type T
+//	 T:  &term{false, T}  == {T}                    // set of type T
-//  ~t:  &term{true, t}   == {t' | under(t') == t}  // set of types with underlying type t
+//	~t:  &term{true, t}   == {t' | under(t') == t}  // set of types with underlying type t
-//
 type term struct {
 	tilde bool // valid if typ != nil
 	typ   types.Type

vendor/golang.org/x/tools/internal/typesinternal/objectpath.go

@@ -0,0 +1,24 @@
+// Copyright 2023 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+package typesinternal
+
+import "go/types"
+
+// This file contains back doors that allow gopls to avoid method sorting when
+// using the objectpath package.
+//
+// This is performance-critical in certain repositories, but changing the
+// behavior of the objectpath package is still being discussed in
+// golang/go#61443. If we decide to remove the sorting in objectpath we can
+// simply delete these back doors. Otherwise, we should add a new API to
+// objectpath that allows controlling the sorting.
+
+// SkipEncoderMethodSorting marks enc (which must be an *objectpath.Encoder) as
+// not requiring sorted methods.
+var SkipEncoderMethodSorting func(enc interface{})
+
+// ObjectpathObject is like objectpath.Object, but allows suppressing method
+// sorting.
+var ObjectpathObject func(pkg *types.Package, p string, skipMethodSorting bool) (types.Object, error)

vendor/modules.txt

@@ -384,7 +384,7 @@ github.com/mattn/go-isatty
 ## explicit; go 1.19
 github.com/microcosm-cc/bluemonday
 github.com/microcosm-cc/bluemonday/css
-# github.com/miekg/dns v1.1.55
+# github.com/miekg/dns v1.1.56
 ## explicit; go 1.19
 github.com/miekg/dns
 # github.com/minio/md5-simd v1.1.2
@@ -849,7 +849,7 @@ golang.org/x/image/tiff/lzw
 golang.org/x/image/vp8
 golang.org/x/image/vp8l
 golang.org/x/image/webp
-# golang.org/x/mod v0.10.0
+# golang.org/x/mod v0.12.0
 ## explicit; go 1.17
 golang.org/x/mod/semver
 # golang.org/x/net v0.15.0
@@ -897,15 +897,17 @@ golang.org/x/text/transform
 golang.org/x/text/unicode/bidi
 golang.org/x/text/unicode/norm
 golang.org/x/text/width
-# golang.org/x/tools v0.6.0
+# golang.org/x/tools v0.13.0
 ## explicit; go 1.18
 golang.org/x/tools/go/gcexportdata
 golang.org/x/tools/go/internal/packagesdriver
 golang.org/x/tools/go/packages
+golang.org/x/tools/go/types/objectpath
 golang.org/x/tools/internal/event
 golang.org/x/tools/internal/event/core
 golang.org/x/tools/internal/event/keys
 golang.org/x/tools/internal/event/label
+golang.org/x/tools/internal/event/tag
 golang.org/x/tools/internal/gcimporter
 golang.org/x/tools/internal/gocommand
 golang.org/x/tools/internal/packagesinternal